Fiber optic connection is the mostly used passive device in fiber optic communication systems, and normally it’s composed with three parts:two fiber optic connectors and an adapter. The two fiber optic connectors are loaded into two fibers;Normally adapters come with metal or plastic flange housings , to fix the connectors. For adapter, there are types of ST,LC,SC,FC,MU,DIN,D4,E2000, LX.5, SMA,MTRJ,VF-45,MPO/MTP, etc. With different structure, there are types of hybrid adapter(Famale to female and female to male), and bare fiber adapter.