Thermatek Thermagear Water Resistant Heated Men's Slippers With TRI-LON PLUS Advanced Soft Shell Fleece- Includes 2 Heat Packs - X- Large TRI-LON PLUS advanced soft shell fleece provides breakthrough for the first time in outerwear products Water resistant for moisture protection in all elements Concealed heat zone pockets keep the heat packs in and your head warm Set of 2 heat packs included provide controlled, targeted heat for up to 8 hours 13x4.875x6.75