Amazon.com: KNACRO 1-Channel 30A High Current 5V Contactor Relay Switch Power Switch DC Power Switching Control Board Module Electrical Relay switches for Cooler Heater Refit Water Heater Control (DC 5V) : Electronics
Amazon.com: Qunqi 5V 2 Channel 5V Relay Module with Optocoupler Low Level Trigger Expansion Board Compatible with R3 MEGA 2560 1280 DSP ARM PIC AVR STM32 Raspberry Pi (2channel-4pc) : Electronics
Amazon.com: Vogurtime 4 Channel 5V Relay Module with Optocoupler Isolation Support High and Low Level Trigger Relay Red Board : Industrial & Scientific
TE CONNECTIVITY/POTTER & BRUMFIELD RTE24005F Power Relay, DPDT, 5VDC, 8A, PC Board : Industrial & Scientific - Amazon.com
5V DC Delay Relay Turn on/Turn Off Module, Delay Relay Delay with Timer Turn on/Delay Turn Off Switch Module (5V) - - Amazon.com