Photonix PX-C108 Optical Singlemode Light Source 1310nm is designed to accurately measure power and loss measurements in the fiberoptic LAN environment. Photonix PX-C108 features an ST Style port, single mode operation, 1300nM operation, 2khz modulation, a durable aluminum body, and low battery indication. Designed to complement LANLITE optical power meters, but works well with any power meter in multimode testing applications.