The K&H Cool Bed III is a great pet bed for keeping your dog cool on hot summer nights and the large bolster sheet will keep him comfortable. This bolster sheet comes with the pillow and is made of a linen blend. The bolster sheet is machine washable. No electricity is required to operate the Cool bed III and these beds are attractively designed and allow a cool spot for dogs. Simply add the recommended amount of water through the easy fill cap and burp with the new easy air adjustment valve. The unique Cool Core diverts the liquid better than ever throughout the bed for advanced cooling power. The new nylon/vinyl exterior is tougher than ever!! Being extremely affordable, the Cool bed III is the choice for any dog owner looking to offer their pet a comfy, dry, cool place to relax. Recommended for indoor and outdoor use.