This mini draft tapping head will turn your Ultimate growler into a portable keg system. The growler and 16gm CO2 bulbs are purchased separately, by click on accessories. This convenient growler tapping head is the best way to keep your precious beer fresh and carbonated in the beer. The pressure applied by CO2 will keep your beer away from damaging oxygen and keep the beer carbonated for ages. The vacuum walled growler will also keep the beer cold for ages meaning you don't even need a chilly bin or cooler box.