The 44492A Reed Relay Multiplexer is ten 2-wire reed relay channels, it is a plug-in for the 3457A Multimeter (pictured above, not included). The maximum voltage (terminal-to-terminal or terminal-to-chassis) is 125 V peak. Thermal offset is <3µV. Closed channel resistance (end of relay life) < 4 ohms. The unit is specified for <100kHz ac volts and frequency operation. Maximum switching and measurement speed is 300 channels/second.