HiLetgo 12V 8 Channel Relay Module With OPTO-Isolated Support High And Low Level Trigger

Very useful relay board with the great feature of being able to select either plus volts or ground to activate individual channels. Most relay cards at this price only trigger on O-volt/ground and is fixed for all channels. This card allows individual selection of channels as triggering either for +volts or ground. In many cases this is not an issue as pulling channel to ground is simple [Arduino boards easily programmed for this] but some control setups can benefit from high triggers.

These are excellent relay modules and highly recommended.

Bought several, all work as expected, you don't need a manual to use these. It's all in the description and written on the silkscreen on the board.

The relays are extremely easy to use with no coding needed only a high pulse from Arduino pin will trigger the relay. It’s to be noted that you do need 12v dc supply to get the relays to operate properly.

Good quality, excellent price.

The media could not be loaded.  Very good quality product. I have used it with my arduino and it does work nicely. Having 8 releys in one products comes handy, specially when trying to drive several motors with one module only.