Waterguard Quilted Cotton Mattress Pad – Cot Size 33” – Soft, Comfortable, and Fluffy Mattress Pad – Waterproof Mattress Protector Stretched 13″ for Snug Fit on Regular Sized Mattress. 100% WATERPROOF MATTRESS PAD: Waterguard Cot Size 33 Mattress Pads are 100% waterproof, which is not an easy task when making a mattress pad that is also made from quilted cotton.