The Snuggle Safe bed heater is the simple, safe and easy way to heat your pet's bed. Simply place it in the microwave for approximately 5 minutes, then, place under your pet's bedding. It will provide approximately 12 hours of safe, comforting warmth. Ideal for new arrivals, elderly or sick pets or travel, and can be used inside or out. 8.5in diameter. Comes with one heat pad cover.