Backing: 100% Polyurethane; Side Wall: 100% Polyester; Surface: 70% Rayon Derived from Bamboo, 30% Cotton Imported BAMBOO & COTTON - A premium blend of 70% rayon from bamboo and 30% cotton creates a breathable, ultra-soft, and moisture wicking surface to keep you comfortable and dry through the night WATERPROOF PROTECTOR - Our quiet proprietary STRATOSMART barrier protects the top of your mattress from all liquids, stains, and dirt with confidence while allowing airflow for a comfortable temperature FITTED SHEET STYLE - Designed to be lightweight so it does not change the feel of your mattress; this secure fitted sheet style protector has deep pockets that stretch to fit mattresses up to an 18-inch depth MASHINE WASHABLE - Keep your bedding clean and fresh with easy-care; This waterproof mattress cover is machine washable and you can tumble dry it on low heat Cal King size mattress protector measures 72 x 84; Confidently backed with our 15-year warranty