Restline Zip-UP Bedbug Proof Mattress Encasement (Double Size) 100% Cotton Full Six Sided Mattress Encasement and Waterproof Cover. 75 x 54” Bed Liner, Invisible Zippered Mattress Cover 12-15" DeepFeatures This fully encased, waterproof mattress protector is your first line of defense between sweat and accidents from the outside, and the inside. The Soft Fabric, Fine Tooth Zipper with Airtight Velcro, and Noiseless Waterproofing ensures you get a good nights sleep, while suffocating protecting your mattress from stains. While other types of double mattress protector claim to be 100% Waterproof, only Restline boasts an impressive Cell Tight TPU