The first one I had lasted four years. Just purchased the second one to replace it. Great product. I use it in a plastic bottom from a plant pot that is about 14 inches in diameter and 2.5 inches deep. Have had temperatures below -30 F this winter and it keeps a spot open even when it is that cold. I have seen others that use 200 watts, but like this one as it only uses 50 watts. I taped the cord to a flat metal strap that can be bent to fit over the top of the plastic bottom from a plant pot.