This is a by Japan NTT developed the optical connector. Case rectangular, use pins and coupling sleeve dimensions identical to the FC. Which pin end surface by PC or APC grinding style; fastening method is the use of plug-pin bolt, without rotation. This type of connector is inexpensive, plug easy insertion loss less volatile, high compressive strength and high mounting density.
ST and SC interface are two types of fiber-optic connectors, for 10BASE-F connections the connectors are usually type ST, 100BASE-FX, type of connector in most cases to the SC. ST connector exposed core, core inside the joints of the SC connector.