Test thoroughly to ensure that a single network cable normally transmits signals. Added wavelength memory function to remember the set test wavelength after shutdown. Press LIGHT in different environments to turn the background lighting on or off as desired. Added LED flashlight lighting function to assist with line control in dark environments. You can perform automatic adjustment of the test reference according to actual test requirements. Encapsulated housing protection can reduce damage to the machine caused by accidental drops to some extent. Features: Test Range: -70 to +6dBm Wavelength Range: 800~1700nm Standard Wavelengths: 850nm, 980nm, 1300nm, 1310nm, 1490nm, 1550nm, 1625nm, 1650nm Accuracy: ±5% 650m red light source (optional): Imw, 10mw, 20mw, 30mw Display Resolution: Linear display 0.1%, Logarithmic display 0.01dBm Battery: 2 * AAA batteries, 1.5V, 250mAh (Batteries are not included in the shipment) Product Size: 130 * 63 * 29mm / 5.1 * 2.5 * 1.1in LRFR strives to provide every customer with the highest standard of customer service.