This is the bottle for the Fallout Jet prop. If you can't find the an old CO2 cartridge from an airsoft or paintball gun, just print this. The mouthpiece can be found at http://www.thingiverse.com/thing:2009087. I designed it using Tinkercad and hope you like it! Check out some of my other designs such as the Lego compatible Halo MA5C Assault Rifle. Even more are on the way soon, possibly including the Halo BR55 Battle Rifle, M6C Magnum, and the ARC-920 Railgun!