Feature: 1. Accurate measurement, high measurement accuracy and backlit LCD display resolution, with user self‑calibration function. 2. Quick response and measurement. When the output power changes, it can display fast tracking and real‑time measurement of optical power. 3. Wide measurement range, can provide 80dB optical power measurement range, absolute optical power measurement and relative power measurement. 4. Six calibration wavelengths: 850nm, 1300nm, 1310nm, 1490nm, 1550nm and 1625nm. 5. Easy to use, real‑time monitoring and display of battery power When the battery power is low, a warning notification will be displayed and automatic shutdown function. 6. The portable optical fiber tester requires 3xAAA batteries(Not Included), has a long battery life, is convenient to carry and use, and is very convenient. Specification: Item Type: Optical Tester Material: Plastic Product Model: TL510 Measurement Range dBm: -70~+10 dBm (the actual best measurement range is -65 ~ 0dBm) Wavelength Range (nm): 800-1650 Calibration Wavelength: 850nm, 1300nm, 1310nm, 1490nm, 1550nm, 1625nm Detector: InGaAs Accuracy: <±3% (-10dBm. 22℃) Resolution: Linearity: 0.1%, Non-linearity: 0.01dBm Working Temperature: -10℃-+50℃ Storage Temperature: -20℃~+70℃ Relative Humidity: 90% (+ 30°C) Connector: Removable for FC / PC SC / PC Power Supply: 3xAAA batteries (delivered without batteries) Working Time:> 120 hours (without backlight). Package List: 1 x Optical Power Meter(Battery Not Included)1 x Adapter Head1 x Storage Bag1 x Manual