Deconovo via Amazon offers its Deconovo Premium Hypoallergenic Waterproof Twin Mattress Protector for $31.99. Coupon code "COU3YUQV" drops it to $15.99. With free shipping, that's $16 off and the lowest price we could find. It's waterproof, measures 39" x 75", and fits mattresses with pockets up to 16". Deal ends May 29.