JSR-A4H is a 4 circuits mercury conductive slip ring, which can transmit 30A and 4A at the same time. It uses liquid mercury as the contact material. Mercury slip ring is also called mercury rotary joint, which is a conductive rotary joint with liquid mercury as the conductive medium. Mercury slip ring using special sealing materials, insulation and conductive technology research and development production, the shell material is aluminum oxide or stainless steel, used for any rotating signals such as: tiny voltage, current, EMF, thermocouple, straingauge, audio-visual signals, high-frequency, computer signals and electrical connections.