Breeders, pet owners and veterinarians have been using K&H Lectro-Kennels™ 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-Kennel™ can lie flat on the doghouse floor or be attached to the wall. An internal thermostat keeps the temperature at a desirable 100 degrees when in use. Lectro-Kennel™ also comes with a free removable, washable fleece cover. Indoor or outdoor use. UL listed.