Review on SainSmart 101 70 100 2 Channel Relay Module by Troy Tec

I used this to control a lamp and it was very easy. They are a lot smaller than the picture, which was good for me as I needed them to be quite small. The terminal block is still large enough to accept a standard lamp cord. There is a clicking sound when switching on and off. It's not too loud, but you can hear it. Some people will say it's annoying, and I suppose it would be in some applications, but there's something very natural about toggling a lamp with one click. The click of a lamp is a sound we've become so accustomed to that it would just seem weird without it. Using the Arduino it was very easy to control it. Actual guides are not included, but these modules are so common that a simple web search can easily find the guides.