Mamoru-kun Waterproof & Anti-Mite Sheet - Family Size This is a waterproof sheet that is dryer-safe. You can protect your mattress with just this one sheet, eliminating the need for a waterproof mattress protector. I purchased it on Amazon, but I ordered the wrong size. I opened it, washed it once, and used it. I then washed and dried it again. I've decided to buy a new one, so I'm offering this to someone who is looking for one. * No fabric softener used. * No laundry detergent with synthetic fragrances used. * No smokers or pets. Please consider this item only if you understand that it is a used item. No returns accepted.