Basically a new rifle, the regulator who came with rifle was removed (adjustable from inside )to install the new external adjustable regulator, also the lock mechanism was removed from the hammer spring, (this is the way it supposed to be ) and the small wheel turns now to adjust how much you need, very accurate, 2 magazines, i prefer pick up, or deliver near by, if posted i need to charge extra. Also there is a rti case that i can add for a price .Thank you for looking