We, Hanguang Electron Device Factory is a key enterprise making electronic vacuum devices .The factory is not only an important base for developing and manufacturing high power klystrons but also one of the designated manufactures of military electronic devices. Main product are as follows: "Hanguang"Brand vacuum interrupter; vacuum circuit breakers, operating device, vacuum interrupter test set ;"Sangong "Brand electric light sources; Specially, since the beginning of the 1985s, Hanguang has produced well over 650,000 vacuum interrupters to date, a high tech product in great demand worldwide. The product range currently comprises vacuum interrupters for circuit-breakers in the range from 12 to 40.5 kV with short-circuit breaking currents up to 80 kA, and interrupters for switch-disconnectors and contactors from 7.2 to 12 kV.