The next generation Proline AEGs by ASG are built to last and outperform the competition. This AEG is made with high quality components to meet the requirements of experienced airsoft players. The Next Generation Proline M15A4 is accurate, durable, and fully compatible with ULTIMATE upgrade parts. This gun is made with realism in mind. The gun has a full metal upper and lower receiver with authentic ArmaLite Inc, trademarks, giving it the look and feel of the real thing. This gun also has a functional bolt catch and bolt release for easy access to the gun's hop up unit. The LE style stock can be adjusted to 6 different lengths for the users comfort. The stock and grips are made of heavy duty polymer for extra durability. The carry handle is removable to reveal a picatinny rail which can be used for adding optics and. The rear sight that is built into the carry handle can be adjusted for windage and elevation. Internally the gun is top notch. The gearbox is full metal with steel gears and ball bearings. It has a ported ball bearing piston head and a 3 steel tooth piston. The cylinder head is reinforced for durability. This gun includes a 360 round high capacity flash magazine. Simply pull the string a few times to fully wind the magazine.