LONG-LASTING: Standard pillow covers are made with a high thread count and a tight weave of the finest quality microfiber fabrics to prolong the life of your pillows. Pillow protectors save pillows from dirt as well as wear and tear. VALUE BUNDLE: This set includes 4 pillowcase covers. These Standard pillow protectors are all machine-washable, so you don’t have to worry about a thing! ZIPPERED PROTECTION: Each pillow case protector has an auto-lock zipper on the side of the pillow, ensuring that dust doesn’t creep in. Plus, having a zipper on the back of the pillow cover keeps it away and out of sight. BREATHABLE FABRIC: Our pillow protectors with zipper standard size are made of extremely soft cooling microfiber. Each pillow case with zipper will keep you cool in the summer and warm in the winter. BREATHABLE FABRIC: Our pillow protectors with zipper queen size are made of extremely soft cooling microfiber. Each pillow case with zipper will keep you cool in the summer and warm in the winter.