This Newport SP-6 Solid Post is made of solid Stainless Steel and is tapped on both ends. One end is tapped 1/4-20 to allow direct mounting to your breadboard or optical table and the other end is 8-32 to accept a broad range of Newport mounts and positioners. This post is 6" long overall. It will fit in all of Newports (and other manufacturers) standard post mounts that accept 1/2" diameter posts.