Durable plastic disk that enables you to safely stack one keg on top of another keg while the design allows BOTH the top and bottom kegs to be tapped at the same time. Inexpensive way to double the floor space in a cramped walk-in cooler and make storing & stacking kegs easier and safer for employees and distributors. Kegs that are improperly stored, moved or stacked can be extremely dangerous and can potentially cause serious injury. Using good-quality keg spacers is a smart investment in your business. There are two size Keg Spacers. This one is to stack standard keg diameters (1/2 Barrels = 15.5 gallons) and Pony kegs (1/4 keg with same diameter as 1/2 barrel = 7-3/4 gallons.) If you are interested in Keg Spacers to stack Sixtel or Torpedo keg diameters (1/6 keg = 5.16 gallons) then type 'Stack!Co Sixtel Keg Spacer' into Amazon search.