Welcome to our store! This 3-IN-1 device combines an optical power meter, LED light, and a 10km red light source for comprehensive fiber optic testing. Features a sensitive chip and robust internal structure for low power consumption and 40 hours of continuous operation. Supports 10 wavelengths: 850nm, 980nm, 1270nm, 1300nm, 1310nm, 1490nm, 1550nm, 1577nm, 1625nm, and 1650nm. Compatible with SC FC ST adapters, meeting most communication technology maintenance needs. The compact design, clear display, and button operation make it easy and practical to use. Red Light Source Detection Distance: 10 km Power Supply: 2 x AAA batteries (not included) Wavelength Range: 850-1650nm Standard Wavelength: 850nm, 980nm, 1270nm, 1300nm, 1310nm, 1490nm, 1550nm, 1577nm, 1625nm, 1650nm Display Resolution: Linear display: 0.1% / Logarithmic display: 0.01dBm Working Temperature: -10-60℃ Storage Temperature: -25-70℃ Automatic Shut-off Time: 10 minutes Continuous Battery Life: Minimum 40 hours Includes: 1 x Optical Power Meter, 1 x Hanging Rope, 1 x User Manual Your satisfaction is our top priority. If you encounter any issues after receiving the product, such as damage or incorrect quantity, please contact us immediately, and we will provide the best solution!