Here's the latest Skirmish Report from Airsoft Extreme which covers the BOLT Airsoft B4A1 AEG... "B.R.S.S. is a revolutionary design with International Patents Register The develop team in Bolt Airsoft has created a powerful recoil system called B.R.S.S - Bolt Recoil Shock System. B.R.S.S is a revolutionary paten .The B.R.S.S is utilized an outstanding designation by kinetic energy reduced by piston which then switches to Recoil weight of stock tube and subsequently displacement occurred to reach the outcome of recoil simulator. Such novel devise has been gone through several tests and accordingly BRSS comes into existence!

• GearBox: Verson 2
• Spur Gear: 95 m/s Powder Metallurgy, 120 m/s Steel Stamping
• Sector Gear: 95 m/s Powder Metallurgy, 120 m/s Steel Stamping
• Bevel Gear: Powder Metallurgy
• Motor: High Torque Motor
• Blowback: YES"