1 2 4 8 Channel High Or Low Level Triggers DC 5/12/24V for Home Smart Control Ho

1 2 4 8 Channel High Or Low Level Trigger DC 5/12/24V High Low Level Trigger Relay Switch with Optocoupler Isolation for Arduino. NO: Normally-open relay interface, the relay is suspended before the relay is engaged, and is shorted todotcom after the relay is engaged.

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