All paintball markers use air pressure from an air tank or 12-gram cartridges to fire a paintball. 300 fps is the maximum allowed at tournaments while 290 fps is the maximum on most playing fields.
Air tanks come in different sizes.
The bigger the tank, the longer you can play before requiring a refill. Sizes begin at 4 oz. and go up to 20 oz. CO 2 TANK Air is pressurized at 750 to 1000 psi. Pulling the trigger activates the hammer. The hammer slides forward, pulling the bolt over the exhaust valve while pushing the exhaust valve forward to the chamber.