1. The ventilation holes on the piston head can greatly increase the speed that the piston travels; thus it increases the speed that the gun fires.
2. The piston head has a rubber cusion which absorbs the force and decreases the noise when it impacts the gearbox.
3. The piston head has a special design which can decrease the friction occurs when the spring compresses. This design not only can prevent the malfuction of the spring, but also increases the durability of it. The longevity of the battery can benefit from this design as well.