The HydraCure S16 single-use wet-curing cover evenly wicks water across the slab surface for a continuous supply of moisture for gradual and controlled curing. Made from a rayon and polyester blended fabric with a white polyethylene coating, it traps the water, maintaining high humidity under the cover, and prevents heat buildup. The smooth fibers won't stain the surface, leave residue behind, or mildew during storage. PNA Construction Technologies. 800-542-0214.