Permafresh represents a break through in technology: It"s long lasting protection helps protect against common bacteria and dust mites. Permafresh 4-Pack Pillow Protector Set Features Permafresh uses 100-Percent polypropylene The set contains 4 Standard 20-inch W by 26-inch L pillow protectors. Machine wash cold, gentle cycle, tumble dry low, do not bleach. Made in China.