Auto telephone exchanger: KJ-1/2/3/4, Auto telephone KH-1SG, Auto telephone KH-1SQ, Auto telephone KH-1T/G, Auto telephone KH-1J, Auto telephone KH-2T/G, Auto telephone KH-2Q, Auto telephone KH-1SF, Explosion-proof telephone KH-1B

Auto telephone exchanger: KJ-1/2/3/4, Auto telephone KH-1SG, Auto telephone KH-1SQ, Auto telephone KH-1T/G, Auto telephone KH-1J, Auto telephone KH-2T/G, Auto telephone KH-2Q, Auto telephone KH-1SF, Explosion-proof telephone KH-1B by Jiaxing Kexun Electron Co., Ltd.. DNV TA certificate TAA00002CJ.