A simple CO2 pressure regulated picnic tap that uses brewery approved gas. US Sankey base fits most US beer kegs. One 74g CO2 TapGas® cylinder will easily preserve and push all of the beer out of 1/6 and 1/4 barrels. A full cylinder will almost push a 1/2 barrel. That's why there are 2 cylinders sold in a package. Regulator is adjustable and carries a lifetime warranty.