The spa Cover Guard is extremely strong, waterproof and designed to work in all climates. Protect your expensive insulating cover from tree sap, ice, snow, harsh rain and intense sun. A 12 in. skirt is included and features an elastic hem for easy installation over the top of your current cover. Please Note: This product is neither a safety cover nor an insulating cover; it is not intended to be a replacement for a standard foam core-equipped spa cover but will further enhance and protect your existing insulting cover and prolong its life.