I have four of these controllers three on fermenting fridges and one as rotational spare. For the price, these controllers are an excellent buy. The instructions can be a bit daunting at first. Just play around with it for a bit and you will see what it can do or just plug it in and set the temperature you require then connect the fridge to it. It will then cycle the fridge keeping to the temperature you have set. If you need a temperature controller for a fermenting fridge or lagering fridge this is the one I would recommend.