MISSION: ALLERGY Barrier II Fabric is the most cost-effective allergen-barrier: allergen-impermeable, soft, and lightweight. It is extremely tightly woven, with a mean pore size of 6 microns to block all allergens, yet is breathable (air-permeable), making it very comfortable to sleep on. It is not hot and sweaty, as are encasing fabrics made with membranes; does not allow any allergen escape, as do many cotton encasings; and does not accumulate surface allergen, as do encasings made with terry cloth or non-woven fabric. MISSION: ALLERGY Allergen-Proof Boxspring Encasings are manufactured with the highest quality sewing construction. The differences are immediately apparent. All seams and edges are bound with seam binding for durability. Placement of the encasing on the boxspring is easier, thanks to super-long zippers that are half the circumference of the entire boxspring! Zippers are of the highest quality, with an interior zipper flap to prevent allergen escape through the zipper webbing (no tape needed). These medical-grade encasings are suitable for adults or children with allergic asthma, allergic rhinitis, or allergic eczema (or simply for good hygiene). They are the ultimate allergen-proof boxspring encasing for comfort, protection, and durability. King and California King sizes are sets of two split sizes. 100% Woven Polyester Microfiber. Ten-year warranty. "... protect both your pillows and your mattress with special mite-proof covers, experts say. Be sure you get covers from a reputable company, like Mission Allergy..." THE NEW YORK TIMES "Much Ado About Dust Mites" 3/4/11 "Say sayonara to dust mites. The fix is to use hypoallergenic encasements on my mattress and pillows. Dr. Fost recommends Mission: Allergy." HEALTH MAGAZINE "How healthy is your bedroom?" 3/9/11