Plastic Mattress Protector Zippered, Waterproof Vinyl Mattress Cover, Heavy Duty Noiseless Mattress Encasement by Blissford

This is exactly what I was looking for. I wanted something truly waterproof for my child’s mattress, as she is recently potty trained. I aired it out outside when first arrived bc smelled slightly of plastic. I put it over mattress (fully covers, mattress slips inside) and then put a traditional mattress cover with padded top on top of this. You’d never know it was there. No noise, no plastic smell. It is big- should fit any size mattress height-wise. My daughter’s mattress is one of the highest I could find and there was room to spare. In fact, I had to tuck some of the excess of this cover under. Padded mattress pad and fitted sheet held excess in place. Definitely recommend if you need something truly waterproof to protect your mattress.