Chill Puck - Beer Can Cooler (12) Chill Pucks use phase change gel originally used by NASA to cool the plutonium cores of orbiting satellites Intended to chill the bottom 1/3 of you beverage to avoid the dreaded warm backwash effect. 1 Chill Puck keep your beverage cold up to an hour. Each Chill Puck is attached to your can using a a silicone band. 6 assorted bands come with each 12 pack of chill pucks One Chill Puck lasts for one can and then should be replaced with a fresh cold one.