electric well fps-300 m4 full auto assault rifle airsoft gun w/ full stock, metal gearbox(Airsoft Gun) Electric Powered (AEG) Full Metal Gearbox Velocity (FPS): 300 with 0.20g BB's Adjustable Hop Up System Integrated RIS for Accessories Can Switch Between Full and Semi Automatic with the Flick of a Switch! Working Safety Removable Front and Rear Aiming Sights Full Fixed Stock High Capacity 500 Round Magazine Requires Ni-Cd 1500mAh 7.2V Battery to run (Included) Length: 24.5" Package Includes: Electric WELL FPS-300 M4 Full Auto Assault Airsoft Rifle Ni-Cd 1500mAh 7.2V Battery with Charger Starter Pack of BB's High Capacity 500 Round Magazine Gun Sling