This heated mat provides safe radiant heat that matches your pet's body temperature. The durable, sanitary ABS plastic pad has a built-in thermostat that works both outdoors and indoors. UL- approved electric cord is coil wrapped to prevent chewing. No moving parts ensures your pet's safety and requires no maintenance. Sizes: Medium (22.5"L x 16.5"W), Large (28.5"L x 22.5"W).