Systema Cylinder Set for Thompson

Non bore up kits are designed to replace all of the air seal components in the gearbox in order to take full advantage of the spring's power. By reducing the amount of escaping air it effectively increases the amount of air propelling the BB, which in some cases can mean more FPS. Systema is and always has been a leader in airsoft engineering, and their upgrade parts, like this cylinder kit, is an excellent upgrade from stock components.