Photonix PX-C221 Techlite Dual Visible Laser Light Source is designed to allow the test technician to test, tune, and troubleshoot MT-RJ assemblies by injecting visible red LASER light into either or both MT-RJ fibers simultaneously. This dual visible laser light source utilizes two 635nm visible lasers which can be operated in CW mode (continuous) or mdulated at 3Hz (flashing), 500Hz, and 2kHz thereby allowing it to be used as tracer signal generators for use with most popular fiber identifiers or optical leak detection probes.