The CASV M4 AEG is another example of an excellent product from Dboys at a very good value. This carbine length AEG has many high end features but without the high end price tag. The gun itself is fully made of metal including the entire front and top rail system. Internally the gun is fully made of metal as well with a full metal gearbox and gears. The stock is adjustable and made of durable ABS plastic. Also included is a verical foregrip which attaches the the bottom rail on the RIS. The battery is housed inside an external battery box. The rear sight is a flip up sight, making it easier to add optics should you choose to. Overall this gun offers a great value whether you're a beginner or an advanced player.