The 2.5 Lb. Aluminum CO2 Tank is a very portable size for when you need to take your kegs on the road. This tank will usually carbonate and dispense 4 or 5- 5 gallon kegs per fill up.
Note: Federal law requires that the CO2 tanks be shipped empty. They can be filled at your local welding supply shop, or look in the phone book under Gas-Industrial, Medical.