All muzzle brake designs share a basic principle: they partially divert combustion gases from the muzzle end of the bore, at a generally perpendicular angle to the long axis of the barrel. The momentum of the diverted gases thus does not add to the recoil. The angle toward which the gases are directed will fundamentally affect how the brake behaves. If gases are directed upward, they will exert a downward force and counteract muzzle rise. Any device that is attached to the end of the muzzle will also add mass, increasing its inertia and moving its center of mass forward; the former will reduce recoil and the latter will reduce muzzle rise.