Fermenting your homebrew at the right temperature is one of the critical factors in making good beer. Let the temperature get out of whack, and you beer will suffer! Forget about dealing with that ugly messy homemade swamp cooler anymore. Cool Brewing Fermentation Cooler is designed specifically to accommodate standard 6.5 and 5 gallon fermenters and carboys. Neatly and easily keep your fermentation temperatures in check. Just add frozen water bottles and switch out as needed to reach the desired temperature. 4 - Two Liter Bottles, 2 in the bag and 2 in the freezer getting cold will keep the bag at temperature on the hottest Florida day. Save time and effort in that The Cool Brewing Fermentation Cooler is sealed, insulated and 100% waterproof so it will efficiently and neatly keep your temperatures in check. When you’re done the Cool Brewing Fermentation Cooler easily folds up for storage until the next brew day!