Aspen Pet¨ Self-warming Bolster Mats are constructed using space blanket technology to create a safe, convenient way for pets to stay comfortable in cooler climates by reflecting and retaining your pet s radiated body heat. No electricity is required. Made with contrasting corduroy and supple faux lambswool plush. Designed for plastic and wire kennels to provide extra comfort. Anti-skid fabric on the bottom. Lightweight for easy transport. Machine washable.