Durable, weather resistant case made of thermoplastic polyurethane and water proof zipper. Quick release mounting system will fit regular seat rails and up to 10mm carbon rails. Interior mesh pocket, elastic band, and lining to keep contents organized. Easy to clean because molded case does not absorb mud, dirt, or water. Size is 3.5” x 4.0” x 6.0” with 37 cubic inches of storage capacity.