OWL WS-MDSDsc Wavesource Single and Multi Mode Quad Wavelength Fiber Light Source is an advanced fiber optic light source that is economically priced and provides high and consistent output. The OWL WS-MDSDsc is designed with temperature-compensated outputs, a simple and intuitive four button interface, clear LED indications, and battery indication to properly monitor output. The OWL WS-MDSDsc also carries a NIST calibration and can perform auto-wavelength adjustment during testing when used in conjunction with an OWL Wavetester.