Cable test function Operation method: Long press UNIT key for 3 seconds to enter RJ45 test mode, then press again to exit RJ45 test mode High-quality imported connector Improved signal penetration and extended service life New LED lighting for dark work environments Selectable wavelengths: 850nm, 1300nm, 1310nm, 1490nm, 1550nm, 1625nm Supports three interface types: SC, ST Maintenance tool with multi-function design Upgraded 3-in-1 functionality: Optical Power Meter + Visual Fault Locator + Network Cable Tester User calibration available Allows user-defined test parameters based on actual needs Press and hold + REF + UNIT buttons to enter user mode; screen displays "CAL" Press REF and UNIT simultaneously to restore factory settings Press UNIT button to decrease value by 0.05dB Press power button to save Press REF + UNIT to restore factory settings Press key to switch between wavelengths Press REF to increase value by 0.05dB Set current test result as reference for relative power measurement; display shows dBm value Detector type: InGaAs Measurement range: -70 to +3 dBm Uncertainty: 5% Display resolution: linear display 0.1%, logarithmic display 0.01dB Red light source wavelength: 650nm Red light output power: over 5mW Operating temperature: -10C to +60C Storage temperature: -25C to +70C Auto power-off time: 10 minutes Battery life: greater than or equal to 48 hours Product dimensions: 118 x 68 x 30mm Power supply: 1.5V AAA x 2 (battery not included) Color: yellow Material: plastic Package contents: 1 x Optical Fiber Tester, 1 x network cable port Package includes only the items listed above; other items not included Note: Lighting and display differences may cause slight color variation between image and actual item. Measurement error allowed within +/- 1-3cm.