Lots of trickery in these Wehrs Machine spring sliders. The smoothest and most stable slider on the market. They use a linear DU bushing on a hardened shaft, along with a shaft stabilizing internal piston. No need to unscrew the nut to remove the spring. The spring cup opposite the adjusting nut is quickly removed with a clip. A four position locking mechanism assists with fine tuning. The Torrington bearing on the adjuster nut allows for easy adjustment and bind free spring travel. Sliders now come standard with our OD alignment cups. This is their 26” extended coarse thread body for 5" OD springs.