This water bottle enclosure is designed to insulate and prevent water from freezing when riding in cold conditions. - Waterproof, 5.5mm neoprene construction with nylon lamination inside and outside - Includes: plastic cage, Allen key, screws and washers - Fits and encloses up to an average 20oz bottle and has enough room for a heat pack - Extended zipper pull for easy open close while riding with winter gloves - Reflective material on logo