ROUND HOUSES: Designed to fit into igloo style houses (Round or dome-shaped) but is also great for sheds, garages, barns, or any sheltered area your outdoor pets hang out THERMOSTATICALLY CONTROLLED: Heated mat automatically responds to temperature changes to warm to your pet's normal body temperature DURABLE: Outdoor dog heating pad features rigid ABS exterior (not flexible), 5-1/2 feet steel wrapped cord and removable fleece cover SIZING: Medium size measures 15 X 24 inches and uses 60 watts; measure your igloo style home’s diameter for the perfect fit SAFETY: This heated pad has been tested & certified by MET Labs and exceeds USA/CA electrical safety standards; K&H doesn't just use safety listed parts, we safety certify the entire product - For indoor/outdoor use with 110/120 volt electrical current only BRAND YOU TRUST: Designed by K&H with OVER 20 years of experience in creating safe, innovative, quality products for pets