The 1588801-1 is a ferrule kit for the PRO BEAM Sr. series of ruggedized, expanded beam fiber optic connectors. It is specifically designed for multimode (MM) applications and features a fiber hole size of 126 μm. This kit is compatible with 2 and 4 channel PRO BEAM Sr. connector inserts, providing a critical component for the optical interface. The PRO BEAM Sr. connector system offers a durable, non-contacting connection that is resistant to dirt, debris, and vibration. These ferrule kits are essential for building or repairing connectors used in harsh environments such as field-deployable communications, marine applications, and industrial systems.