ThermoCube® is a unique and patented electrical device. Plugs into a standard electrical outlet which turns the power on and off automatically, according to outside temperature. Power flows when temperatures fall to 35° and power stops when temperatures rise to 45°. Typical applications include use with heat tapes, bucket or utility de-icers, heat lamps and engine block heaters.
I ordered one of these to plug our milk room heater into so that we weren't needlessly heating it overmuch. It seems to be doing the trick, our electric bill is going down, and my medicines and supplies are staying liquid! The holes are a little tight fitting, and it does take some muscle to get the plugs inserted.
I use this to control my heated bucket. I use it during the fall and spring when temperatures vary more and buckets dont always need to be heated (normal winter is always below freezing). Then I dont have to plug and un plug or remember to. Helps me save energy too.