Many older style tubas are equipped with "S" style linkage assemblies. Due to the introduction of the Rod End bearing, or Uniball, much of the noise and lost motion of the "S" linkage can be eliminated. Maintenance is relatively low and bearing life is extremely high. This style of linkage removes the flexible, spongy feeling of the old linkage producing a solid, positive action. The action rods are adjustable allowing the player to set the paddle height. Most tuba manufacturers are now supplying new horns with this feature due to player demand.