Blue Magic - Night Rest Freeflow Waterbed Mattress: * Full motion mattress for your hard-side waterbed * Precision design with reinforced corners for strength and durability * Made from the highest quality vinyl * Superior lap seam construction * Eco-friendly vinyl exceeds US and European standards * Durable 18 mil. vinyl thickness * Requires 8 oz. of waterbed conditioner to be added each year to prevent the growth of micro-organisms * Generously sized vinyl completely fills out a wooden waterbed frame