King Size National Allergy Premium 100% Cotton Zippered Pillow Cover Protector. This cover is hypoallergenic making it ideal for those with allergies. This is one pillow protector. Featuring a zip closure, this machine-washable pillow protector is easy to remove and clean. It measures 21X37 inches, making it a perfect fit for king-size pillows. Protect your pillows and enhance your sleep with this premium quality pillow cover protector from National Allergy.