Review on ARCELI KY 019 Channel Module Arduino by Omar Obong

So all the pins that can be done is to turn on the working LED so that the side of the pin faces you, left positive center is negative, the right one must be a switch. Applying power or negative does not activate the switch but for my needs and time I modified it to work when you turn it contact side towards you, the first 2 big solder points activate the relay. left positive, right negative 5v gives you an audible click, now it works so yes it's a bit buggy, need to change to use it