wrong & missing information regarding the board -
You don&tt2;t get what you see on the Product Picture and description.
it&tt2;s a cheap board, usually there is not much you can fail with such a 16 way relay board. But if there are no correct wiring instructions coming with the board, you must fail. The product picture suggests, that it is similar to sainsmart board - IT IS NOT!! if you power 12V on the sockets to power the relays, you have 12V at the 5v PIN TO the Raspberry or other device that will definitely destroy anything connected.
This lesson (yes, it&tt2;s my fault - I didn&tt2;t checked it properly before connecting the power) costs me now 5x the price of the relay board in a raspberry & 7"Touch - just because somebody in China decided to safe 0.005 € for a piece of paper with PIN Layout or at least a warning message.
Next time I will buy again from regional store, even if it costs double price.