The basis of the G4-A3 Series was to use the cylindrical Dragon Fire RIS Unit. Airsoft GI wanted to build a high performance AEG with a strong, light, and stable RIS Unit. The Dragon Fire RIS was perfect. It is one solid piece, which counteracts the wobble that comes from a standard two-piece RIS. It is also made of Aluminum so the weight is relatively light, yet very durable and burly. The Dragon Fire is also a free float system which provides more shooting accuracy than a two-piece system.