This is the new AEG Electric M4 SPR FPS-400 Airsoft Gun. This M4 Airsoft rifle is classified as a Special Purpose Rifle (SPR)by the military and is used by the elite special forces. Made of full metal, including the internals, 1/1 scale, and coming with a high power motor, you can experience realism like no other with this gun. This M4 SPR also features an extendable butt stock, RIS rails, flip up fore and rear sights, and a high capacity magazine.