well d4815 m4 electric airsoft gun full & semi auto fps-300 full metal gearbox retractable stock high capacity magazine working safety(Airsoft Gun) Features: 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 Retractable Stock High Capacity 500 Round Magazine Requires Ni-Mh 8.4V 1100 mAh Battery to run (Included) Length: 23.5" (Collapsed Stock) Length: 26" (Stock Extended)