Norbert's Folding Panel Mats are filled with crosslink polyethylene and two feet wide panels fold accordion-style for easy storage and transport. Extremely durable 18 ounce vinyl covers are stitched with dacron thread. All Norbert's Folding Panel Mats have two inch hook and loop fasteners permanently attached on both short sides for end-to-end attachment. Hook and loop fasteners on all four sides is a recommended option for wider matted areas. Sorry, custom mats are not eligible for a refund.