Fibre optic adaptors are used in patch panel,wall outlets and active equipment as docking port for patchcords. They are available for all different connector types, like SC, LC, FC, ST etc. as either simplex, duplex or quad (singlemode only) version. Multimode adaptors usually have brass alignment sleeves inside to fit the connector ferrules together, whereas single-mode adaptors use Zirconia ceramic split sleeves