Our Pit Pillow is an extra soft gymnastic mat with very loan density foam in a denim cover * It is designed to mimic the feel of a mat on a loose foam pit and be placed on another foam or air mat * The 3 ft x 4 ft x 8 in Pit Pillow is NOT intended for use on hard surfaces or alone * It has Velcro on all sides, so that several can be connected end-to-end, side-by-side or stacked vertically * The Velcro also allows the Pit Pillow to connect to our other smart mats, such as the Baby Bear or Mama Bear mats