Grade B BIF fiber patch cable is designed to meet large bandwidth and high speed requirements of the latest active optical equipment, allowing large streams of data to be transmitted reliably over long distances. High quality zirconia ferrules. LC, SC, FC, MU connectors. The differences between optical fiber grades A, B, C, and D primarily pertain to the quality of the fiber end-face, which significantly impacts performance metrics such as insertion loss (IL) and return loss (RL). insertion loss of random mating of grade B patch cable is ≤0. 0dB especially for APC. ality of the cabling components becomes. Mechanical values such as apex offset, radius of curvature and. IEC Grade B is based on IEC 61753-1, which is stable with excellent random mating performance between each grade B connector.