Fiber optic adapter for connecting single-mode optical fibers with SC/UPC connectors. The ceramic holding pin high quality, polished at an 8-degree angle, reduces the reflection of the transmitted signal. Locking mechanisms facilitate installation and removal. The Simplex cable type is used in cable channels, distribution panels, and conduits with low mechanical loads. Single-mode optical fibers transmit light in a single direction, with low reflection and less dispersion. SC connectors offer quick and easy connection, secure attachment, and connection reliability. They are used in telecommunications, video devices and media converters, LAN, WAN, and CATV networks, sensor systems, measurement applications, and railway networks.