Fibre optic adaptors or fibre optic couplers are used to terminate or link the fibre optic cables or fibre optic connectors between two fibre optic lines. By linking two connectors precisely, fibre optic adaptors allow the light sources to be transmitted at most and lower the loss as much as possible. Each fibre optic adaptor is individually and rigorously tested and certified under fibre optic inspection processes to make sure low insertion loss, good interchangeability and reproducibility.