Provide clamping force to secure optics to our kinematic platform mounts, stages, and V-clamps.M4 Threaded Hole on Top and M4 Threaded Stud on Bottom of Post.M4 Threaded Hole on Top and M4 Threaded Stud on Bottom of Post.M4 Threaded Hole on Top and M4 Threaded Stud on Bottom of Post.Used with Prism Platform or Prism Mounts together.