5V 1 Channel SSR G3MB-202P Solid State Relay Module 240V 2A Output with Resistive Fuse For Arduino M63. Module interface: Input section: DC +: positive power supply (by relay voltage power supply) DC-: connect power negative CH: Relay module signal to trigger the end (low to trigger effective) NOTE: Power must be DC Voltage, voltage must be consistent with the relay voltage Package Included: 1 X 5V Solid State Relay Module