Built-in recoil system in buffer tube Reinforced Metal Construction 14.5-inch full metal outer barrel Quad RIS for accessory customization Internals feature LONEX OEM parts High precision reinforced V2 Gearbox w/ 8mm bearings Polycarbonate piston and head w/ 13 half-teeth Removable polymer foregrip for improved stability Flip-up front and rear iron sights are great backups in case your optic failsSpecifications: Operation Electric AutomaticBuild Metal Upper/Lower Receiver, Polymer Grip, StockFiring Modes Semi-automatic, Full-automatic, w/ Functional SafetyMuzzle Velocity 400-420 FPS (w/ 0.20g BBs)Gearbox Full Metal Version 2Magazine 360rd High Capacity (gear wind-up)Battery 11.1V LiPO (Not Included)Inner Barrel 363mmHop-Up AdjustableWeight 6.8 lbsOverall Length 32 in. / 35.5 in. (Retracted / Extended) 1X AEG