Secure A Bed Mattress Encasement, 100% Waterproof, Zipperd, Certified Against Bed bugs, Dust Mites, and Allergens Terry Top Lab tested and certified against bed bugs, dust mites, and allergens, and 100% Waterproof to protect against spills, bed wetting and stains. Locking zipper technique for maximum protection. Membrane Breathable Material allows air to circulate, but repels liquids. Highly durable even after countless washing and drying.