The circular connector is adopted very reliable hyperboloid line reed as conduct contact.It has such characters as little contact resistance,easy using,anti-vibration shock-resistance and high reliability.Its main technical indexes conform to TB/T2716-1996 of Chinese Railway Department.The boyonet socket joint is adopted between socket and plug,so that it can be easily and operated conviniently.It is widly used for the connection among the electrical and electronic equipments for the railway,electricity,etc. Complying with the customer’s requirement,the plug and receptacle can be mounted with pins and sockets.