This Officially Licensed Colt M4 AEG has a lightweight yet durable polymer construction that keeps both the cost and weight down. While the exterior may be polymer, the internals such as the gearbox are metal making for long lasting performance. This high quality gun features official Colt trademarks and high quality construction. The gun has a full metal version 2 gearbox with steel gears. The required 8.4v NiMH rechargeable battery and charger are also included (a 9.6v battery can also be used). The stock is retractable and can easily be adjusted to the shooter's preference. The top carry handle can also be removed to reveal a 20mm rail where an optic can be mounted. This gun is OEM by JG.