Yeti Rambler Colster 12oz Slim Can Insulator The Yeti Slim Can Colster is ideal for keeping hard seltzers icy cold on the hottest days. The Yeti Rambler Colster is a can insulator with double-wall vacuum insulation that will keep slim 12 oz. cans chilled. The Rambler 12oz Slim Can Colster features a newly evolved Load-and-Lock gasket. With just a quarter-turn, the gasket secures your can in place. Available in plain stainless steel or with a Duracoat color, this colster is constructed of thick-g