Feature: 1. 2 BACKLIT MODES: Default smart mode when turned on, with no operation for 3 minutes to automatically turn off the backlit. In off mode, press the LED key to switch to intelligent mode. 2. WAVELENGTH MEMORY FUNCTION: Added memory function to remember the test wavelength set before shutdown. No need to repeat settings. 3. RECOGNIZABLE FIBER TRANSMISSION FREQUENCY: Accurately identify the fiber transmission frequency, which can be used to determine the lighting mode and whether it continuously emits light during engineering construction. 4. INTELLIGENT STANDBY MODE: The automatic shutdown function is enabled by default when turned on, and it will automatically shut down after 10 minutes without any operation. 5. 2 UNIT DISPLAY: Press the (UNIT) key to select dBm, dB, and uW units in sequence. The test data will be displayed with the corresponding results. 6. EASY TO USE: Fiber power meter supports FC, SC, ST common interfaces, detachable metal pen heads, easy to replace ceramic cores. Specification: Item Type: Visual Fault Locator Material: ABS Wavelength Range (nm): 800 to 1700 Probe Type: For InGaAs Measurement Range (dbm): -50 to +26 Uncertainty: ± 5% Standard Wavelength (nm): 850, 980, 1270, 1300, 1310, 1490, 1550, 1577, 1625 Display Resolution: Linear Display: 0.1% Logarithmic Display: 0.01dBm Red Light Working Wavelength (nm): 650 Output Distance (km): Approx. 15000m / 49212.6ft Frequency Identification (Hz): 0, 270, 1000, 2000 Number of Offline Saved Data (PCS): 40 Input Voltage (V): 3-6 Working Temperature (℃): -10 to +60 Storage Temperature (℃): -25 to +70 Automatic Shutdown Time (min): 10 Battery Continuous Working Time (h): Greater than or equal to 48 Battery Type: 3.7V rechargeable lithium battery 600mah x 1 [shipped with built in battery] . Package List: 1 x Optical Fiber Power Meter 1 x Data Cable 1 x Manual