Used Length Measuring System for sale (62,422)

Condition: good (used), Year of construction: 2016, functionality: fully functional, machine/vehicle number: 7512-3901-FA, We will provide more detailed information about the equipment during a personal on-site visit, which we recommend. Hedpjzphu Eofx Afgow

Condition: used, Wente CamSorik GmbH Laser measuring system / 3D laser measuring camera Wente CamSorik LaserCam_hs LC691103 Complete laser measuring system with tripod system, laptop, LaserCam_hs software, and documentation For sale is a used laser measuring system from the manufacturer Wente CamSorik GmbH. The system is suitable for non-contact measurements, 3D measurement technology, quality control, position detection, as well as industrial measuring and automation tasks. Technical data: Manufacturer: Wente CamSorik GmbH Model: LaserCam Type: LaserCam_hs Serial number: LC691103 Year of manufacture: 2018 Made in Germany Laser class: 2 Wavelength: 630–690 nm Laser power: < 1 mW Standard: EN 60825-1:2007 Network interface: Ethernet (RJ45) IP address: 192.168.1.121 Dimensions of sensor unit (approx.): 620 × 240 × 240 mm (L × W × H) Total weight including accessories and tripods: approx. 28 kg Software / Laptop: Acer TravelMate laptop LaserCam_hs Version 7.2.10.555 Wente CamSorik GmbH LaserCam_high speed documentation available Equipment: LaserCam_hs sensor unit COLA receiver / transmitter LED ring light Ethernet interface Industrial connector 2 × Manfrotto professional tripods Acer laptop including power supply LaserCam_hs software Documentation Connection cables and accessories as shown in the pictures Application areas: Industrial measurement technology 3D measurement technology Quality control Robotics and automation Research and development Production monitoring Scope of supply: Wente CamSorik LaserCam_hs LC691103 2 × Manfrotto professional tripods COLA receiver / transmitter Acer TravelMate laptop including power supply LaserCam_hs software version 7.2.10.555 LaserCam documentation Connection cables and accessories as shown in the pictures Condition: Used Laptop and LaserCam_hs software have been started. Optical condition as shown in the pictures. Normal signs of wear and tear. The table shown in the photos and other items not explicitly mentioned are not included in the sale. Hsdpfsz Ndq Hox Afgsw Shipping by freight forwarder is possible. Subject to change, errors and prior sale. We will gladly answer any further questions by telephone.

Condition: excellent (used), Year of construction: 2014, functionality: fully functional, type of input current: three-phase, input voltage: 400 V, measuring range X-axis: 254 mm, measuring range Y-axis: 152 mm, measuring range Z-axis: 100 mm, workpiece weight (max.): 45 kg, feed length X-axis: 254 mm, feed length Y-axis: 152 mm, feed length Z-axis: 100 mm, travel distance X-axis: 254 mm, travel distance Y-axis: 152 mm, travel distance Z-axis: 100 mm, input frequency: 50 Hz, S-T Industries Profile Projector 22-2600 – 30" Screen, 5X Magnification | Precision Optical Comparator Now available at Used Machine Tools Ireland Ltd – a high-precision S-T Industries Profile Projector, Model 22-2600, with a large 30" (760mm) viewing screen, Heidenhain Quadra-chek 100 Control and 5X magnification lens, ideal for dimensional inspection in precision manufacturing. Previously used in a medical device company, this optical comparator is in very good condition and has been maintained to the highest standards. S-T Industries Profile Projector 22-2600 | 30" Screen | 5X Magnification | Very Good Condition 🔧 Manufacturer: S-T Industries 📍 Location: Ireland 📅 Model: 22-2600 🧰 Condition: Very good – ex-medical device company 📦 Available: Immediately 🛠️ Technical Specifications: Brand: S-T Industries Model Number: 22-2600 Control: Heidenhain Quadra-Chek 100 Screen Size: 30" (760mm) diameter Magnification Lens: 5X Worktable Travel (X-Y): 10" x 6" (254mm x 152mm) Hedpfew Nyfwsx Afgew Glass Stage Plate: 12" x 8" (305mm x 203mm) Load Capacity: Approx. 45 kg (100 lbs) Screen Rotation: 360° with digital readout Illumination: Surface (Oblique) Illumination – Halogen Profile Illumination – Collimated light with adjustable brightness Focus Travel (Z-Axis): 4" (100mm) Power Supply: 230V / 50Hz Condition: Very good – ex-medical device company Country of Origin: USA Location: Ireland 🧭 Ideal For: Medical device manufacturing Aerospace & precision engineering Tool & die inspection Quality control and dimensional inspection labs S-T Industries Profile Projector for sale Used optical comparator Ireland 30" screen profile projector Precision measuring equipment Dimensional inspection projector 22-2600 comparator S-T Industries 5X magnification projector Used metrology equipment Notes: *Specifications are given in good faith but not guaranteed*

Condition: excellent (used), For sale: a professional, digital height gauge by Mitutoyo (model 192-613) – Japanese precision and reliability in one device. Ideal for workshops, quality control, and precise measurements. Specifications: Hsdpfx Ajz Slawsfgew • Measuring range: 0–300 mm • LCD display – clear readings even in low light • Functions: ZERO/ABS, PRESET, HOLD • Power supply: CR2032 battery • Stable base for secure support and precise measurement • Original – Made in Japan Condition: The equipment is fully functional and well-maintained.

Condition: used, For sale: PREWI industrial measuring table designed for dimension control of furniture components, panels, and carpentry parts. Technical data: Hsdpfezc Hwyex Afgow - Measuring area: 2800 × 1050 mm, Z = 65 mm - Digital readout: HEIDENHAIN ND 5023 3X - Measurement in 3 axes - Stable industrial construction - Complete guides and measuring system - Accuracy: Absolute accuracy X/Y +/- 0.10 mm - Typical repeatability X/Y +/- 0.02 mm - Relative accuracy Z +/- 0.05 mm - Typical repeatability Z +/- 0.02 mm - Resolution: 0.01 mm Condition: - Machine is in working order - Inspection possible before purchase - Digital readout functions correctly - No technical documentation available Applications: - Dimension control of furniture panels - Measurement of furniture fronts - Verification of components after CNC machining - Quality control of production The machine is currently in a production facility and is ready for further operation. Inspection and testing of the machine are possible on-site by prior arrangement. For technical questions regarding the measuring table, please call Andrzej at 789 487 841.

Condition: excellent (used), functionality: fully functional, Very good leak calibration device in a case. Hsdpjxz R Apofx Afgsw And other measuring cases available upon request!

Condition: excellent (used), For sale: WTW LF320 meter, fully functional and in good condition. We can assist you in finding a cost-effective freight forwarding company or courier service. Hedoz Skrljpfx Afgjw

Year of construction: 2020, condition: excellent (used), functionality: fully functional, Mobile 3D coordinate measuring machine - Flexible 3D measurements at any location Image guided 3D coordinate measuring machine Keyence Measuring System WM-3000 Coordinate Measuring System XM-2000, XM-1600 Digital Inspection Station TECHNICAL DETAILS camera chip: 4 MP CMOS Measuring range: 600 x 300 x 200 mm Smallest display unit: 1 µm Smallest angle: 0.0001 Repeatability (locked): +- 3 µm Table load: max. 25 kg Display: 15" TFT Initial purchase: 12/2020 Coordinate measuring system Measuring head: WM-3000 Camera tripod: WM-S1 Tripod extension / stand for measuring head: WM-EX1 Measuring software: incl. laptop Additional software 3D-CAD import/export: WM-H1C WM Battery charger: WM-BC1 Probe battery: WM-B1 Stylus: OP-88422; 2.5 mm Mouse: WM-M30D User manual: German Euro AC power cable: OP-99032, OP-99033 Attachments for camera realignment: OP-88546 Calibration cone for needle probe: OP-88547 Magnets for attachments camera realignment: 972344 Digital test station measuring head: XM-2000 Digital test station control unit: XM-1600 Additional software 3D-CAD import/export: XM-H1C XM Mouse, Keyboard: XM-M26E User manual: English AC power cable: OP-99031 MACHINE DETAILS Hsdpfopz Ityjx Afgsw Main electrical connection: 24 V Weight measuring head: 25,0 kg Weight tripod: 4,5 kg Weight extension: 4.0 kg

Condition: used, functionality: fully functional, With this offer, you are purchasing a used “Keyence VHX-970F” digital microscope Items for sale: 1x Keyence VHX-970F with We can easily configure the machine to meet your specific needs. Please feel free to contact us! Condition: This listing is for a used device, which may show signs of use (minor scratches or discoloration). The unit has been tested to ensure it is in working order Packaging and Shipping: You are welcome to view the unit during our business hours. Please schedule an appointment! Seaworthy packaging and worldwide shipping are available upon request! A functional test will be recorded on video for you prior to shipping or pickup. For more information, please feel free to contact us directly. Hedpfx Afszpvdbogsw

Condition: like new (used), The JAI GO-5000M-PGE is a professional monochrome industrial camera designed for use in machine vision systems, quality control, industrial automation, and measurement applications. Thanks to its high-quality image sensor and GigE Vision interface, the camera ensures stable data transmission and reliable operation in demanding industrial environments. Large quantities in stock – approx. 72 units. The price listed is for 1 camera. It is possible to purchase the camera as a complete set with KOWA lenses (LM12HC, LM16HC, LM25HC, LM75HC), MidOpt BP635-40.5 filters, and a protective housing. Other JAI industrial cameras are also available: GO-5000M-USB, GO-2400M-PGE, GO-5000C-PGE, and GO-5101M-PGE. The GO-5000M-PGE model performs excellently in production inspection systems, dimensional measurements, object identification, and advanced image processing applications. Its compact housing and wide compatibility with machine vision software allow for easy integration with existing systems. Applications: - Machine vision systems, - Quality control and production inspection, - Industrial metrology, - Industrial automation, - Research and development (R&D) laboratories, - Measurement and control systems. Key features: Hjdpfozkak Iox Afgjw Manufacturer: JAI Model: GO-5000M-PGE Type: Monochrome industrial camera Interface: GigE Vision (Gigabit Ethernet) High image quality Compact industrial housing Easy integration with machine vision systems Designed for continuous operation in an industrial environment The equipment comes from the inventory used in research and development projects related to vision systems, metrology, and industrial automation.

Condition: excellent (used), As a result, the FAG Detector III is particularly useful for detecting: • imbalance and misalignment. • rolling bearing damage. • gear damage. Hsdpfx Afez Skqzsgow

Condition: used, functionality: fully functional, In this listing, you are purchasing a second-hand ‘Keyence VL-500’ 3D coordinate measuring machine Items for sale: 1x Keyence VL-500 with the following features Includes software Includes additional software Includes a laptop for operation Includes a calibration plate Ready for immediate use Condition: This listing is for a second-hand device, which may show signs of wear (minor scratches or discolouration). Hodpfx Asy Iaa Tsfgjw The unit has been tested to ensure it is in working order Packaging and dispatch: You are welcome to view the unit during our business hours. Please arrange an appointment to do so! Seaworthy packaging and worldwide dispatch available on request! A functional test will be recorded on video for you prior to dispatch or collection. For further information, you are of course welcome to contact us directly.

Condition: excellent (used), Year of construction: 2014, functionality: fully functional, machine/vehicle number: PH-54114, For sale: high-precision optical measuring machine/scanner – VICI VISION - Model: MTP 120 – 230 SCEPM - Year: 2014 - Serial No.: PH 54114 For sale: a complete, high-precision optical measuring scanner—in like-new condition—designed for the accurate and rapid measurement of complex geometries, including radii, angles, irregular bores, gears, complex curves, ellipses, etc. The device offers high precision and is suitable for the rapid generation of inspection certificates meeting the strictest standards (e.g., for measuring Swiss watch gears). The measuring system has been maintained and serviced by the manufacturer, VICI VISION. It is an indispensable tool for serial production. The unit is connected to the power supply and ready for immediate operation. Hedpfx Asz Iyrksfgjw

Condition: excellent (used), For sale: SaluTron D2 paint thickness gauge. Hjdpez Skqnofx Afgjw

Condition: like new (used), Year of construction: 2018, functionality: fully functional, warranty duration: 3 months, OFFER FARO QUANTUM 2.5E + SCAN HD Quantum E 2.5m 7 Ejes Serial No W25-E5-17 Hedpfevvt N Eox Afgjw Model 2100 Volumetric 50m Quantum M 2,5m 7 axis includes Arm with Bluetooth and Wireless technology, calibration kit, base, plate, 3mm probe, 6mm cables, heavy-duty case, rechargeable bat Polyworks inspector Standard Package, the universal 3d metrology software platform for dimensional inspection, node-locked license. 2023 (no Mantenimiento) Calibración ENAC, basado en la norma ISO 10360-12:2016 Opcional 8 AXIS + POLYWORKS 2023 + TRIPODE

Condition: excellent (used), Year of construction: 2020, machine/vehicle number: 2299.001, For sale is a high-quality Modular Mass Production Tester (MPT) from NTS Optel – a professional testing and measurement system designed for automated quality control of optical components such as wafers, sensors, or micro-optics. This machine was developed for precise high-volume inspection of optical components and delivers the highest measurement accuracy, reliability, and flexibility for industrial applications. Thanks to its modular design, the tester can be perfectly adapted to specific production or development requirements. 🔍 Features & Equipment • Integrated laser module (940 nm, circularly polarized) for precise optical illumination • High-resolution camera with automatic calibration and large field of view • Robot-based wafer handling (EFEM) for automated loading and unloading • Analysis software for evaluating efficiency, contrast, uniformity, and performance • CE-certified, including safety interlock and cleanroom-compatible design • User-friendly control via touchscreen and integrated GUI system • Connectivity for LAN, power, and compressed air (6 bar) ⚙️ Technical Advantages • Automatic image capture and evaluation of test specimens (DUTs) • Supports customer-specific software modules (DLLs) • Low maintenance, robust construction, high operational reliability • Optional: Z-axis control and wafer flip station 💡 Applications Ideal for research, development, quality assurance, and series production in the following sectors: • Optoelectronics • Sensor manufacturing • Semiconductor technology Hjdsy R Dzgjpfx Afgjw • Microsystem technology

Condition: excellent (used), Year of construction: 2018, Model IM-7010, Model Year 2018 Type: Measuring Head Model with Transmitted and Reflected Light Image Sensor: B/W CMOS, 1", 6.6 megapixels Display: LCD Monitor, 10.4" (XGA: 1024 × 768) Lens System: Dual Telecentric Lens Image-based Measurement Measuring Range: - Standard Measuring Mode: 200 mm × 200 mm (4 × R50) - Precision Measuring Mode: 125 × 125 mm Display Resolution: 0.1 µm Repeatability (without stage movement): - Standard Measuring Mode: ±1 µm - Precision Measuring Mode: ±0.5 µm Repeatability (with stage movement): - Standard Measuring Mode: ±2 µm - Precision Measuring Mode: ±1.5 µm Hodpfxeyc N Ego Afgjw Measurement Accuracy (±2σ): - Without stage movement: - Standard Measuring Mode: ±5 µm*1 - Precision Measuring Mode: ±2 µm*2 - With stage movement: - Standard Measuring Mode: ±(7 + 0.02l) µm*3 - Precision Measuring Mode: ±(4 + 0.02l) µm*4 External Remote Input: Voltage-free input (with and without contact) External Output: I.O./N.G./FAIL/MEASUREMENT Photo-MOS Output: Rated load 24 V DC, 0.5 A, ON-resistance max. 50 mΩ Interfaces: - LAN: RJ-45 (10BASE-T/100BASE-TX/1000BASE-T) - USB 3.1: 4 ports (rear) - USB 2.0 Type A: 2 ports (front) Recording: 500GB Hard Drive Illumination System - Transmitted Light: Telecentric transmitted light illumination (green LED) Ring Illumination: Reflected light (ring light) with four segments XY Stage: Travel range 100 × 100 mm (motor-driven), max. load capacity 5 kg Z Axis: Travel range 75 mm (motor-driven) Power Supply: 100 to 240 V AC, 50/60 Hz, max. power consumption 430 VA Environmental Resistance: - Pollution Degree: 2 - Overvoltage Category: II - Ambient Temperature: +10 to +35 °C Relative Humidity: 20 to 80% RH (non-condensing) Weight: approx. 30 kg

Condition: good (used), Year of construction: 2007, input voltage: 230 V, measuring range X-axis: 250 mm, measuring range Y-axis: 250 mm, measuring range Z-axis: 570 mm, overall weight: 315 kg, - Universal measuring device for measuring tools in transmitted light (2D) and incident light. - Easy to use thanks to photorealistic input dialog on 2 displays and automatic cutting edge recognition. -Swivel device for radial and axial measurement in incident light. - Special measuring programs for radius contour, rake and clearance angle, chamfer width, wobble compensation, step drills, concentricity and much more. - Contour progression measurement >lasso< with nominal/actual comparison. - Incident light image processing >metis 2D< - Protocol editor >Matrix< Technical data Travel Z 570 mm X 152 mm Measuring range - Longitudinal axis Z 570 mm - Diameter 250 mm - Repeat accuracy ± 0.002 mm - Setting accuracy < 2μ - Display accuracy 0.001 mm Hodpfxsqc Tkbe Afgew - Positioning accuracy 0.001 mm - Concentricity accuracy 0.002 mm Optionally, another machine can be offered as a spare parts carrier. However, this is defective.

Condition: used, Renishaw Type: Equator 500 Year of manufacture: 2021 Item description: For sale is a Renishaw Equator™ 500, a high-precision, industrial 3D measuring and testing system for in-process and quality control in manufacturing. The Equator 500 is not a conventional coordinate measuring machine, but a comparative measuring system specifically designed for fast, repeatable measurements directly in the production environment. Ideal for serial production, in-process measurements, and automated inspection processes. The device is ideally suited for dimensional, form, and positional tolerance testing of workpieces and can be used to provide feedback to CNC machines. The software starts correctly, system status according to the display: "Started OK" (see photos). Functions & Applications 3D measurement of workpieces Comparative measuring principle (very fast inspection cycles) High repeatability in the µm range Real-time temperature compensation Suitable for shop floor use Automation capable (e.g. robot loading) Ideal for serial, sample, and process control Typical industries: CNC manufacturing Metalworking Automotive / supplier industry Machine and tool building Technical data (manufacturer's data / approximate values) Manufacturer: Renishaw Model: Equator™ 500 (H+150) Device type: Comparative 3D measuring system / CMM Measuring range: X / Y: Ø approx. 500 mm Z: approx. 150 mm Measuring principle: Comparative coordinate measuring technology Temperature-compensated measurement Accuracy: Very high repeatability Measuring accuracy in the µm range (application and strategy dependent) Control & Software Controller type: Equator 500 Software version: 2.5.21.1 RRTLOS version: 5.1.12 Operation via PC-based Renishaw software Electrical data Supply voltage: 230 V AC Frequency: 50 / 60 Hz Power consumption: approx. 1 kW Dimensions (approx.) Overall height: approx. 1,900 mm Hodpfxjzix Nmo Afgjw Footprint / diameter: approx. 1,200 mm Weight (approx.) 130 kg Condition: used Scope of delivery: (See image) Renishaw Equator™ 500 measuring system Controller / Industrial PC Monitor Keyboard and mouse Base frame Accessories as shown in the photos (Changes and errors in the technical data are subject to change!) We will be happy to answer any further questions you may have by telephone.

Condition: ready for operation (used), Year of construction: 2018, functionality: fully functional, machine/vehicle number: W25-M5-18-17210, number of axes: 7, The measuring arm was last calibrated in October 2024. The laser scanner was calibrated in April 2024. TECHNICAL DETAILS Measuring system: FARO Quantum M ScanArm Measuring range: 2.5 m Axes: 7 Measuring method: Tactile coordinate measurement and 3D scanning Laser scanner head: FARO LLP HD, Revision 3.2 MACHINE DETAILS Application areas: Dimensional inspection, CAD component comparison, first article inspection (FAI), production control, tool and fixture inspection, and reverse engineering Measuring stand height: 750 - 1,000 mm Measuring stand weight: 17.25 kg Reach: 350 mm EQUIPMENT FARO LLP HD laser scanner head, Revision 3.2 Tactile probes MetrologyWorks Kodiak HDP-KCF measuring stand Measuring stand construction: Carbon fiber/aluminum Measuring stand mounting ring: 3"-8 Original FARO transport case Batteries Power supply Cables Mounting accessories Calibration documentation Technical documentation Manual Hedpozx N Rgofx Afgow Note: The laptop and PolyWorks software are not included in the offer.

Condition: used, Horiba Type: Mexa 7100D Horiba exhaust gas system Mexa 7100D Including JAG-10-000-061 cylinder cart, approx. 1200 x 1064 x 802 mm and OVN-724A Stationary exhaust gas measurement before/after exhaust aftertreatment, evaluation of exhaust aftertreatment systems Modal analysis (dynamic or transient analysis) during non-stationary operating conditions Hjdpfszdy Rnox Afgew Analyzer for CO/CO2 (HC, NO, N2o, SO2), O2, THC 200 operating hours Weight 620 kg Year of manufacture 2016 Collection from our location Condition: used Scope of delivery: (See image) (Changes and errors in the technical data are subject to change!) We would be happy to answer any further questions you may have by phone.

Condition: like new (used), Year of construction: 2025, operating hours: 2,025 h, functionality: fully functional, machine/vehicle number: 25-168-T-402; 25-068-F-100-P, overall weight: 200 kg, Equipment: documentation/manual, A Soco System packaging line is offered, consisting of an F-100-P bottom flap folding machine and a T-402-5-2-9 carton sealing machine. Minimum carton width: 320 mm, maximum carton width: 520 mm, maximum carton length: 900 mm, machine dimensions X/Y: approx. 750 mm/1150 mm. Soco T-402 5-8-7 carton sealing machine, carton length range: 200 mm-750 mm, carton width range: 120 mm-460 mm, carton height range: 95 mm-470 mm, sealing capacity: 18/min, maximum tape roll diameter: 385 mm, weight: approx. 200 kg. Includes safety guard and powered conveyor belt, 500 mm wide. The system is in new condition, was put into operation in January 2026, and has only operated for approximately 75 days in a single-shift operation. Documentation is available. An on-site inspection is possible. Hodozvp Uyjpfx Afgjw

Condition: like new (used), Year of construction: 2024, operating hours: 120 h, functionality: limited functionality, For sale is a high-quality digital microscope, the KEYENCE VHX-7000 – a fully integrated system for material analysis, defect analysis, quality control, research, and industrial inspection. The VHX-7000 combines ultra-high-resolution 4K imaging with intuitive operation and advanced measurement functions, including automatic focus stacking, image stitching, 2D/3D measurements, and multi-angle observation. As one of the world's first digital 4K ultra-high-precision microscopes, the system delivers exceptional image quality at SEM level while combining the speed and ease of use of optical microscopy. Included configuration: Main system: KEYENCE VHX-7000 Controller Unit Hsdpfxjy U Iy Is Afgsw Camera: KEYENCE VHX-7020 High-Performance Camera Optics & Adapter: KEYENCE VH-Z20T Zoom Lens / Objective (20x–200x) KEYENCE VH-K20 360° Multi-Function Side View Adapter KEYENCE VHX-20T Tripod Adapter Mechanical components: KEYENCE VHX-S750E Motorized XYZ Stage (40 mm) Software & Accessories: KEYENCE VH-H5M 3D Measurement Software KEYENCE VHX-A70D Console for the VHX-7000 Swiss power cable/adapter Original manuals Key features: 4K Ultra-HD imaging Seamless magnification from 20x to 6000x Fully motorized operation Multidirectional lighting Real-time 3D and roughness analysis Automated focusing and positioning User-friendly touch operation Ideal for industrial inspection, electronics, materials science, metallurgy, and R&D laboratories

Condition: good (used), Year of construction: 1999, functionality: fully functional, machine/vehicle number: 0509, input voltage: 230 V, For sale is an analogue presetting device Zoller Bravo 2. The item is in good condition. Presetting device Zoller Bravo 2 Serial number 0509 Hodjxwlpcspfx Afgew Year of manufacture 1999 Voltage 230 V∼ L/N/PE Frequency 50/60 Hz Tolerance (voltage) −10% to +6% Pneumatics (compressed air) 4−6 bar Power

Condition: excellent (used), I am offering for sale a professional LeCroy WaveJet 354A digital oscilloscope, designed for laboratory, service, and industrial applications. This is a high-quality measuring instrument with a bandwidth of 500 MHz and a sampling rate of 2 GS/s. Technical specifications: • Manufacturer: LeCroy • Model: WaveJet 354A • Bandwidth: 500 MHz Hodpjz Snrbjfx Afgow • Sampling rate: 2 GS/s • 4 analog channels • USB port • Built-in carrying handle • Power supply: 90–264 V AC, 47–63 Hz Condition: • Used, in good visual condition with normal signs of use. • The device powers on and functions correctly – the display is working, as can be seen in the photos.