Your gun isn't going to shoot itself is it? You're going to need some air. C02 is the cheapest and most readily available source there is, so why not start here?
20oz Co2 Tank Features:
•High quality aluminum 20 Oz Co2 Tank with industry standard pin valve, just screw it in and get ready to shoot some people.
•Brand may vary, but currently include Empire Pure Energy and Guerrilla Air
•Approximately 1100 shots per fill, never have to worry about running out of air mid-game. Brand may vary depending on what is currently available.
•We receive fresh tanks weekly, You will not receive out of date tanks
•10.5" length and 3" width
•20 oz Tank weight Empty - 1.75 lbs Full - 3lbs
All co2 tanks are shipped empty to comply with Department of Transportation laws