Review on ARCELI KY 019 Channel Module Arduino by Tim Ram

So all pins that can do is turn on the power LED so the side of the contact facing you left positive center negative right should 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 little buggy, need to change to use it