Chillin Brew panels can keep beer at the perfect drinking temperature, longer than ice. Powered by a non-toxic, biodegradable active ingredient, these panels freeze at 28 degree F., just above the temperature beer would freeze. Add a panel or 2 to ice to keep it frozen 50% longer. Place panels in freezer for 6 to 10 hours or until frozen solid. Place in cooler with pre-chilled beer between panels for best results. Return to freezer to recharge, active ingredient will not wear out from repeated use.