Foam plyoboxes can help eliminate the risk of injury associated with high-intensity box jumps compared to steel plyoboxes. This plyobox set is manufactured with a high density EPE foam, that does not break down. Each box is wrapped with a zippered, easy to clean, replaceable vinyl cover with anti-slip textured top surfacing for added safety. The boxes are color coded for quick identification. You can use 1, 2 or all 3 to make different heights.