Fermzilla 30L All Rounder Fermentation JacketThis jacket is designed to insulate your FermZilla 30L ALL ROUNDER during the colder months to keep your fermentation at the optimum temperature. It can also be used with a heating belt wrap to warm up the wort if the heat from the fermentation isn't enough. Also completely blocks any light UV to prevent light stuck beer. This is ideal if you aren't planning to use your Fermzilla in a temp controlled fridge.