This is a Doggy Man pet heater for dogs. The size is M. I bought it 13 years ago when I got my dog, but my dog didn't like it and never used it. It's not new and unopened, but it has been used very little. Please understand that it has been stored at home. Please consider it as a used item. Please refrain from purchasing if you are looking for a perfect item or are very particular. Please do not ask for a price reduction.