Carolina Gym Supply Closed-Cell Crosslink FoamMake sure to get some rolls of Carolina Gym Supply Closed Cell Crosslink Foam to cover your spring floor underneath your Carolina Gym Supply Floor Exercise Carpet! Closed cell crosslink foam is a polyethylene product that is used in a lot of gymnastics matting. You'll see it in carpet bonded foam, panel mats, competition landing mats, trampoline pads, etc. One of its primary uses is as a layer of padding between your spring floor deck and your floor