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Amazon.com: HiLetgo 12V 8 Channel Relay Module with OPTO-Isolated High and Low Level Trigger 8 Ways Relay Switch Module for Arduino : Industrial & Scientific
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ANMBEST 10PCS 12V Relay Module with Optocoupler High or Low Level Trigger Expansion Board for Raspberry Pi Arduino: Amazon.com: Industrial & Scientific
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Amazon.com: KeeYees 5pcs 1 Channel 5V Relay Module Board Shield KY-019 LED Indicator for Arduino + 3pcs 20CM 10Pin Female Male Jumper Wires : Electronics
MCIGICM 2 Channel DC 5V Relay Module for Arduino UNO R3 DSP ARM PIC AVR STM32 Raspberry Pi with Optocoupler Low Level Trigger Expansion Board : Electronics