This optical laser light source is a stabilized high-performance light source used in the installation and maintenance of fiber optic networks. The application range of the OPTISource Quad Wavelength SM/MM 850/1300/1310/1550 nm fiber optic light source, due to its high-quality construction and reliability, includes fiber optic attenuation measurement, fiber optic signal loss measurement, and fiber optic cable identification through light source modulation. There are three models available: 850/1300 nm for multimode networks, 1310/1550 nm for singlemode networks, and a dual device for multimode and singlemode networks covering all four wavelengths. It features four wavelengths, three model combinations (850/1300 multimode, 1310/1550 singlemode, 850/1300/1310/1550 dualmode "all in one"), continuous wave and modulated signals at 1 kHz, 2 kHz, and 270 Hz, auto-identify wavelength display (fully compatible with Hobbes Optical Power Meter), LED indicators, and auto power off for energy saving.