Have upgraded this thing to the max as a labor of love. Shimmed, lubed, and tuned to run forever. V7 gearbox is a tank. Throw some optics on there and you have a ready-built DMR. Parts List: Guarder SP 120 tune up kit (standard ratio Gears, bushings, tappet plate, Cylinder, Piston, Piston Head, steel bearing spring guide) Guarder SP 130 spring SHS aluminum air nozzle Prometheus 420mm TBB Tru-Hop bucking w/ concave spacer AMP High Torque motor 16 awg wiring, deans connectors Gate Nano ASR mosfet M14 scope mount Laylax bipod stud mount Comes with 2 hi-caps and 3 mid caps Problems: Fire selector is fully functional but has some wobble due to a damaged arm. A piece of the trigger guard is broken- does not affect fit or performance This cost me $500 to build altogether (and a lot of time at the workbench) Buyer pays shipping