FC fiber optic adapter
There are three kinds of FC fiber optic adaptors, square type, single D type and double D type, all FC fiber optic adaptors are made with metal housing, single mode FC Fiber optic adaptors are with zirconia sleeves, multi mode FC fiber optic adaptors are with bronze sleeves. All FC fiber optic adaptors are simplex.

SC fiber optic adapter
SC fiber optic adaptors are all with plastic housing, there are different colors: blue for single mode PC, green for single mode APC and beige for multimode PC. All SC fiber optic adaptors are flange type, single mode adaptors are with zirconia sleeve while multimode fiber adaptors are with bronze sleeve. SC fiber optic adaptors are available with both simplex adaptors and duplex adaptors.

ST fiber optic adapter
ST fiber optic adaptors are all threaded type, with metal housing, single mode ones are with zirconia sleeve and multimode ones are with bronze sleeve. ST fiber optic adaptors are simplex adaptors.

LC fiber optic adapter
LC fiber optic adaptors are all plastic housing; there are simplex LC adaptors
and duplex LC adaptors, usually duplex LC fiber adaptors are with SC footprint. The LC fiber adaptors colors are same as SC fiber optic adaptors: blue for single mode PC, beige for multi mode PC and green for single mode APC. LC fiber optic adaptors are with bronze sleeve for multimode and zirconia sleeve for single mode.

MT-RJ fiber optic adapter
MT-RJ fiber optic adaptors are with polymer housing, there are two types available, one is flange type; another is SC footprint type, both simplex. MT-RJ fiber optic adaptors are black color.

MU fiber optic adapter
MU fiber optic adaptors are available with both single mode and multi mode, they are patch panel mount type fiber optic adaptors.

E2000 fiber optic adapter
Typical E2000 fiber optic adaptors are available by single mode PC and single mode APC, they are simplex fiber optic adaptors, SC patch panel mount type.