Retro Arms, the Czech airsoft upgrade parts maker sent info about their new Retro Arms Version 2 Gearbox. These are fully milled gearboxes which we think are now using AW EN7075 T6 rather than 6061 T6... "The gearbox has long been tested on a spring M160 without any signs of wear and tear. Gearbox is fitted with 8 mm ball bearings, hardened steel connecting bolts and screws for mounting grips. The gearbox is significantly amplified throughout the entire length of the added material. Of course, the use of standard parts for gearbox version II. Both halves of the gearbox to fit together with absolute precision bearings including holes that are 100% aligned."

More photos of the new gearbox at Retro Arms Facebook Page. Also check out their SR25 Gearbox, for those looking for that rare upgrade gearbox shell for the SR25 AEG.