The F-PM850 Polarization Maintaining Fiber offers low attenuation and excellent birefringence for high performance applications. This Corning PANDA PM fiber has a 850 nm operating wavelength with beat lengths ranging from less than 1. Each cable is individually tested to ensure the specified extinction ratio and insertion. These polarization-maintaining fiber optic patch cables are terminated on both ends with high-quality, narrow key, ceramic FC/PC connectors, featuring high-quality polish with a typical return loss of 50 dB.