1It has 6 light wavelengths to choose from, 850nm/1300nm/1310nm/1490nm/1550nm/1625nm. 2Universal optical interface design, it supports for FC/SC/ST, and can convert between absolute power dBm and relative power dB. 3Ergonomic design, its compact structure is specially designed for installation, operation and maintenance of optical fiber, and is not restricted by the use of space. 4Simple operation, you only need to follow the instructions on the operation, it can easily detect the accurate value. 5A wide range of applications, suitable for fiber CATV engineering, fiber optic sensing research, optical device production, fiber optic device research and other fiber optic projects. Item Type: Optical Power Meter Model: GM65 Material: ABS Battery: 2x1.5V AAA Battery (Battery Not Included) Uses: It is suitable for fiber CATV engineering, fiber optic sensing research, optical device production, fiber optic device research and other fiber optic projects. Power Measurement Range -70dBm~+6dBm Standard Wavelength 850nm, 1300nm, 1310nm, 1490nm, 1550nm, 1625nm Display Resolution 0.05 Measurement Error When -48dBm, 2dBm When -48dBm, 3.5dBm Use Environment-48dBm Temperature Range: 0~40 (32~104) Humidity Range: 5~95% Use Environment -48dBm Temperature Range: 0~32 (32~89.6) Humidity Range: 5~80% Storage Environment Temperature Range: 0~40 (32~104) Humidity Range: 5~95%1 x Optical Power Meter (Battery Not Included) 1 x Manual