This waterbed mattress pad has generous pockets to help keep it on. It is quilted cotton and puffs up to about one-quarter of an inch on top. It fits the waterbed smoothly and will pay for itself in energy savings. Mattress pads protect your mattress from damaging skin oils and is a line of defense against punctures. In addition, your skin needs breathing room from the vinyl mattress that a set of just waterbed sheets can not provide.