If shopping for a Split King or Split Cal King mattress, you will need to purchase (2) protectors of your chosen size for adequate coverage. Lightweight and fully washable, our Cooling Mattress Protector provides a 5-sided barrier for the top and sides of your mattress against moisture, allergens, dust mites, mold, mildew, and stains. Designed to provide responsive, cooling coverage across your sleep surface throughout the night, our award-winning Cooling Mattress Protector features mineral-based FRÍO® rapid chill cooling fibers that channel your body heat through each cooling thread, moving heat away from your body before it can accumulate in the bedding surrounding you. FRÍO® Cooling Fibers– Cool 5x faster than traditional polyester Tunnel heat away from the body while you sleep Offer a cooler sleep surface for uninterrupted rest Find relief from sleep heat.® Women's Choice Award: Our entire collection of premium protectors—including our Cooling line—are the official protectors of the Women’s Choice Award.