Bargoose Fitted Mattress Cover - TWIN Protects mattresses from dirt, dust, and other allergen build-up. 100% Polyester Tricot coated with 4 mil vinyl Waterproof. Zippered cover with self-locking, rust-proof polyester zippers. Breathable, waterproof barrier allows for regular air circulation through mattress and bedding. Fabric tested and certified to be bite proof and bedbug proof.