Product review (5 stars): excellent control!
I bought this item so I could use a dysfunctional deep freezer as a brewing fermentation fridge.  I set the controller at 68 degrees, and every time I opened to freezer to check my fermentation, the temperature gauge in the freezer read 68 degrees.  Excellent control and super easy to use.  I've only had it for a month, but it's been great.  Hope it lasts a long time.  I plan to do a lot of brewing!