It features internal thermostats that automatically adjust the temperature to create a comfortable resting space for dogs and cats. It is pre-set to heat to your pet's natural body temperature of 102°F. When plugged in but not in use, it maintains a temperature that is 10-15°F higher than the ambient room temperature. This product is designed for simplicity: there’s no on/off switch to operate. The gentle heat generated will not exceed your pet’s natural body temperature allowing them to enjoy hours of warmth. Warmer easily slides into any zippered dog or cat bed and for beds with at least ½ inch of padding between the warmer and the bed surface. This is a Pet Bed Warmer, that should only be used within your pet's bed and must never come into direct contact with your pet. Each size of the Pet Bed Warmer uses less energy than most light bulbs, helping you keep your electrical bills low. The K&H Lectro-Soft has been rigorously tested and certified by MET Labs, ensuring that it adheres to strict electrical safety standards.