Welcome to our store! 2 BACKLIGHT MODES: Default smart mode when on, without use for 3 minutes to automatically turn off the backlight. In off mode, press the LED button to switch to intelligent mode. WAVELENGTH MEMORY FUNCTION: Added memory function to remember the test wavelength set before shutdown. No need to repeat settings. RECOGNIZABLE FIBER TRANSMISSION FREQUENCY: Accurately identify fiber transmission frequency, which can be used to determine the lighting mode and whether it continuously emits light during technical construction. INTELLIGENT STANDBY MODE: The automatic shutdown function is enabled by default when on, and it will automatically shut down after 10 minutes of no operation. 2 UNIT DISPLAY: Press the (UNIT) key to select dBm, dB, and uW units in sequence. Test data will be displayed with corresponding results. EASY TO USE: Fiber power meter supports FC, SC, ST common interfaces, detachable metal pen heads, easy to replace ceramic cores. 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 Saved Offline 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 Operating Time (h): Greater than or equal to 48 Battery Type: 3.7V rechargeable lithium battery 600 mah x 1 [shipped with built-in battery]