Features QUICK RESPONSE: Optical power meters are simple to use, plug and play, and function quickly and precisely. has a calibration mechanism and a built in relative power calculation for easier use. IMPROVE EFFICIENCY: The testing is substantially simplified and working efficiency is greatly increased by the simple operation. LONG BATTERY LIFE: Optical fiber power meter uses little electricity and can run continuously for 40 hours. suitable for usage outside. GENERAL APPLICATION: 10 wavelengths and a light source are the range. with SC, FC, and ST adapters, 850, 980, 1270, 1300, 1310, 1490, 1550, 1577, 1625, and 1650 nm. addressing the bulk of maintenance requirements for communication engineering. EASY TO CARRY: LED optical fiber power meter is lightweight and tiny, making it simple to take around and store when not in use. Specification: Item Type: Optical Fiber Power Meter Material: ABS Power Supply: Built in 3.7V lithium battery x 1 capacity 650mAh (shipped with built in battery) Power Measurement Range: -70 to +10dBm Probe Range: For InGaAs Wavelength Range: 850 to 1650nm Standard Wavelengths (nm): 850, 980, 1270, 1300, 1310, 1490, 1550, 1577, 1625, 1650 Display Resolution: Linear Display: 0.1% Logarithmic Display: 0.01dBm Working Temperature (℃): -10~+60 ℃ Storage Temperature (℃): -25~+70 ℃ Automatic Shutdown Time (min): 10 minutes Battery Continuous Working Time: Not less than 40 hours Package List:1 x Optical Power Meter  1 x Manual 1 x USB Cable  1 x Hanging Rope   Package List 1 x Optical Power Meter 1 x Manual 1 x USB Cable 1 x Hanging Rope