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Relay Boards With I/O :: 8 Channel RS232 Relay Board W/ISO Input Port and DC Power Terminal Block
4-Port Relay Expansion Board for PHPoC Blue and Black IoT Boards PES-2401N – Envistia Mall
Configure Contact Input and Relay Ports
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USB Relay Controller Board - 4 Channels for Home Automation
2 in 1 DC 5V 8Channel USB Serial Port Relay Module UART RS232 TTL Switch Board
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16ch DC 12V Serial Port DB9 UART RS232 Relay Module for PLC PC Com 3D – Many Favours
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