Check out my page for other items of interest! I reasonable offers on most items, combine shipping when possible on multiple purchases, and ship within US only! Untested condition Features Fully polished "Silver Edge" gearbox increasea overall efficiency by up to 15% from standard gearbox designs Made from high strength zinc alloy; reinforced in key areas for longevity 8mm stainless steel bearings provide smooth travel for the steel gear set Ported cylinder optimized for carbine length inner barrels (~363mm) Integrated "quick spring release" function for easy spring change "Hybrid" electric blowback design (can be disabled simply by changing the mock bolt) Wired to the rear with a Small Tamiya plug Correct to my knowledge