Our Allersoft Non-Membrane Encasements are the newest technology in allergy relief bedding. The tight-weave construction requires no polyurethane or vinyl membrane to protect from allergens. The absence of a solid membrane keeps the encasement air-breathable and cool to the touch while still protecting from allergens as small as four microns. With a 250 thread count, this fabric looks and feels just like a soft cotton sheet while locking out pesky dust mites and specks of pet dander. Zippered cover stays securely in place and provides dramatic allergen reduction over unprotected bedding.