In the Box Specifications: Gearbox SpecificationsType Full Metal Version 2 (Rear Wired)Shell Construction AluminumShell Color BlackMotor High Torque Long TypeGears High Torque SteelBushings 6mm MetalSpring M120 Standard PitchSpring Guide Full MetalCylinder Metal PortedCylinder Head PolymerPiston Polycarbonate w/ 1 Steel ToothPiston Head Polymer PortedAir Nozzle PolymerTappet Plate Reinforced PolymerWiring Standard Wiring (Rear)Lower Receiver SpecificationsConstruction PolymerCompatibility Complete Polymer Upper ReceiversWeight 2.2 lbsColor Black w/ Tan Grip California Proposition 65 Warning: Cancer and Reproductive Harm - www.P65Warnings.ca.gov