The 2.0 inch (50.8 mm) 9316-K Adjustment Screw provides smooth, wobble-free adjustment combined with exceptional long-term stability and low susceptibility to thermal variation. It is the same 1/4-80 precision screw used in our optic mounts and allows you to build your own mounts or positioners. In addition to a travel of 2.0 inch (50.8 mm); the screw has a ball tip, unbraked brass bushing, and is Hex-key adjusted.