The TW3205C from Techwin is an InGaAs-based Optical Power Meter with an optical range from 800 to 1700 nm. It can measure power from -40 to +20 dBm with a resolution of 0.01 dB. This power meter can measure 4 calibrated wavelengths (850, 980, 1310 & 1550 nm) to measure absolute power in optical fibers. It uses three 1.5 V alkaline batteries that can operate up to 360 hours and has an auto-off function for saving energy. This power meter is available in a module that measures 115 x 60 x 20 mm with FC (interchangeable SC, ST) and 2.5 mm universal optical connectors. It is ideal for maintenance in telecom, maintenance CATV, test lab of optical fibers, and other fiber optic measurements applications.