It holds enough air for several kits-worth of painting... Three or so, I'd reckon... Even at .75 cents a pop, it's better than the alternative, which is prop-cans... Were I to really have to go for a while, I'd just drag a spare tire from the car into the shop...
Overall, I'm not sayin' you don't need a compressor, I'm just saying that you don't have to wait until you you can afford one before you can start airbrushing. Personally, I bought new in-box Testors's compressor off Ebay for 21.00 plus 14.00 shipping, and the exact same one retails at Hobby Lobby for 114.00... I still like my tire though, since I do a lot of painting at night and 3 feet away from a sleeping wife... If I find a tire adapter for the compressor, I'll fill the tire myself rather than run down to the gas station.
I just wanted to help get the guy up and running ASAP... The tire is a great interim solution, IMHO...