The Levinsohn Allergy Guard Mattress Protector utilizes 3 layer technology with micro-porous fabric that effectively protects against dust mites and allergens. For even more protection, this allergy blocking mattress cover features ultrasonic seal technology to ensure full closure at every seam. Designed with a full encasement zip closure, your mattress will stay clean from dust and dirt and is sealed tight inside. This mattress protector is also water resistant and blocks sweat and other moisture from ruining your mattress. This allergy mattress cover is made with 50 percent polypropylene and 50 percent polyethylene yet is quiet during sleep.. Lining is made of polyethylene film to block even the smallest allergens.This full size hypoallergenic mattress cover measures 54 inches by 75 inches and is machine washable.