The best way to protect your mattress from stains or being soiled is to use Simmons Beautyrest mattress protector. Simmons mattress protectors feature the unique Expand-A-Grip benefit to hold mattress protector firmly to mattress. The Expand-A-Grip feature allows the mattress protector to fit 4″ to 15″ thick mattress. Its glove-like fit allows proper sheet fit. Filled with polyester fiberfill and antimicrobial-treated fabric, it helps to eliminate household dust mites and protect the fiberfill from growth of mildew and control odors. It is 100% cotton-made, making it very comfortable and it adds an additional layer of breathable comfort to your mattress. It is machine washable.