If you like your beer crisp and cold, you'll love how these glasses keep it icy on hot days. Especially useful if you brew your own beer or buy growlers. Pilsner-style cups are double-walled BPA-free plastic with a unique gel inside. Once frozen, the gel will keep beer at a refreshing 43°-53° F. And while the cups are chilly, your fingers won’t be. A silicone band makes the cups comfortable to hold. For best results, freeze cups upside down for 2 hours or more. Hand wash only.