King Size 78 in. x 80 in. Quilted Mattress Pad. The top of the mattress pad is cotton for comfort, and the fill is 100% polyester for some cushioning. There is stretchy material along the entire perimeter of this mattress pad including the pockets for a sure fit. This pad lays directly on the top of the mattress for protection. This mattress pad is not waterproof. Proudly made in the USA! This mattress pad is cold water machine washable with a cool tumble dry, no bleach.