ULTIMAT 4&#39;X6&#39;X1 3/8" - Fasteners Ends only Use: P.E., Gymnastics, Cheerleading, Martial Arts and more 18 oz. Vinyl cover uses double reinforced,nylon stitched inverted seams to create a smooth surface 1 3/8" firm cross-linked Foam designed for support in high impact activities Fasteners On Ends Only; So mats can be connected Our firmest and lightest mat Size/Color: 4'X6'X1 3/8" - Royal Our firmest and lightest Mat Ultimat&#174; mats provide the firm support necessary for high impact activities by older and heavier users.&nbsp; Use in physical education, gymnastics classes, cheerleading and martial arts training and more 4 x 6-feet x 1.375-inch