ASGTC It's environmental cylindrical reverse bayonet coupling connector with self-locking system, which guarantee a fast locking and unlocking. Designed for Railway and Mass Transit industry. GTC family is high performance, rugged sealed connector with water proof IP67 rated, robust shells for high temperature resistance and resistant to vibrations & shocks. Inserts are available in plastic. Contacts available in gold and silver plating. Zinc alloy plating available.