A new 5 lb CO2 tank is one of the required purchases when you’re changing over from bottling to kegging your beer.
This brand new, 5lb aluminum CO2 tank ships free in the 48 contiguous states, and because it is made of aluminum rather than steel you can feel confident that it will never rust. It’s called a 5lb tank because it holds 5lb of compressed (liquified) CO2. 5lb of CO2 is enough to dispense 8-9 5 gallon kegs of homebrew.
All new CO2 tanks are shipped empty and will require either filling or exchanging for a full tank. Most local homebrew shops will stock gas to exchange, and many local welding supply companies can fill tanks on site.
CO2 tanks should always be stored in an upright position.