An ST (Straight Tip) adapter is a type of optical fiber connector and used to join fiber optic cables with ST connectors. With key characteristics:Bayonet-style Locking Mechanism Design, Durability, Single-Mode and Multi-Mode Applications, Simplex and Duplex. Although newer technologies like SC and LC connectors have become more common in telecom applications, ST adapters still be found in telecommunications systems, particularly in older installations.