According to the different coupled optical fibers are classified as follows:SC 1x2 single mode fiber coupled: Applied to SC fiber interface, it looks similar to RJ-45 interface, but SC interface is more flat, the obvious difference is the inner contact plate, if it is 8 thin copper contact plate, it is RJ-45 interface, if it is a copper column, it is SC fiber interface.LC1x2 single mode fiber coupled: Applied to LC fiber interface, connector to SFP module, it is made of easy to operate modular jack (RJ) latch mechanism. (Commonly used in routers)Fibre Channel1x2 single mode fiber coupler: Used for Fibre Channel fiber interfaces. The external coupler is reinforced by a metal sleeve and tightened by a turnbuckle. Generally used on the ODF side (most used on the distribution frame)ST 1x2 single mode fiber coupled: Used in the ST optical fiber interface, usually used in optical fiber distribution frame, shell is round, fastening method is turnbuckle. For 10Base-F connections, the connector is usually of type ST. Often used in optical fiber distribution frame)