Another look at the Wraith Aero Stock from Wolverine Airsoft, a closer one this time... "Here is a closer look at some of the old and new features of the Wraith Aero Stock for the Wolverine Airsoft MTW. The Aero allows you to power the MTW with an external tank and air line. The Aero allows you to use a 13 cubic inch HPA tank right in the stock of the MTW, providing roughly 1,000 shots per tank. These are available at your local Airsoft retailer or at shop.wolverineairsoft.com/aero."