Our Super Chill series serveware is prized for its polished presence and superb temperature-regulating abilities. Each coaster is made of double-walled stainless steel, with a gel-based unit designed to keep your drink chilled for hours without ice, preventing condensation from forming and creating messy water rings on your surfaces. Double-walled stainless steel construction Place coaster insert in freezer prior to use; inner gel freezes like ice and holds its temperature Won't leave water rings on tabletops or fine furnishings Hand wash only A Frontgate exclusive. At Frontgate, our primary focus is quality. We guarantee that every product we sell will stand up to the supreme test – our customers' satisfaction. To learn more about our policies, visit our Shipping & Processing, Returns & Exchanges and Warranty & Price Guarantee pages.