Protect-A-Bed Luxury Waterproof Pillow Protector, King Thermo-regulating fibers are the coolest waterproof protector to sleep on Waterproof: Polyurethane film backing repels liquids like urine and sweat Breathable barrier fabric and unique Breath-A-Vent for maximum airflow while sleeping. Fits king size pillows. Dimensions: 21 x 37 in. One protector per package.