Breeders, pet owners, and veterinarians have been using Lectro-Kennelsâ„¢ to warm pets for more than 40 years. This new sleek, smooth design is now more comfortable and durable than ever! Constructed of rugged ABS plastic with a steel wrapped cord, the Lectro-Kennelâ„¢ can lie flat on the doghouse floor or be attached to the wall. An internal thermostat keeps the temperature of the pad warmed to your pet's normal body temperature. Lectro-Kennelâ„¢ also comes with a free removable, washable fleece cover.Â Indoor or outdoor use. External Thermostat is recommended for whelping puppies, animals recovering from surgery or those who cannot move off the pad. Thermostat does not come with pad. One year limited warranty.