It is the most popular connector for multimode fiber optic LAN applications. It has a long 2.5mm diameter ferrule made of ceramic (zirconia), stainless alloy or plastic. It mates with a
  interconnection adapter and is latched into place by twisting to engage a spring-loaded bayonet socket.
		   
  ST Connector
  Singlemode, Multimode, Simplex and duplex are available.