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Great quality.
very good
Great for Arduino which can't handle high power directly.
This one doesn't come with instructions but it works great. You need to remove the Jumper Between VCC and JD-VCC. JD-VCC must be wired to +12V and GND to -12V. VCC must be wired to +5V and GND to -5V. The optocoupler works as low and high input which means you must go from input pin to whatever switch you have. Then you just go from the switch to ground. (5V source ground) (NO or NC... whatever it will only change in which switch's position the relay gets activated.) If you did everything correctly you should see a red led light up when the relays are activated. Hopefully this review will help you save time !
Quality is Good...
Relais excellent
Quick delivery, Good quality as advertized.....
parfait