This is part of a system of prints that turns an OpenBeam into an optical rail. This part connects 8mm rods, which hold optical components, to the optical rail. An optical rail is a long, straight, sturdy rail onto which optical components such as light sources and lenses can be bolted down and easily shifted along the length of the rail. Commercial optical rail sells for $380/m ($115/ft). Open beam only costs $12/m for the fancy black anodized stuff. You get the idea. This component is part of the Open-source optics project, whose goal is to radically reduce the cost of scientific optical hardware: by the [Michigan Tech's Open Sustainability Technology Research Group]( http://www.mse.mtu.edu/MOST). For similar see the Open-Source Lab How to Build Your Own Hardware and Reduce Research CostsOpenSCAD code included for modifications. Just print on your favorite open-source 3D printer and clean up. You will want to flip the stl for easy printing. You'll need an M3 Nut and screw. Put the screw through the rod holder and screw onto the OpenBeam with an M3 nut. You can get Open Beam at http://www.openbeamusa.com/Extrusions/ This project was developed by the Michigan Tech Open Sustainability Technology research group http://www.mse.mtu.edu/MOST Thanks to Terence Tam for Open Beam. This component is part of the Open-source Optics Library: Zhang C, Anzalone NC, Faria RP, Pearce JM (2013) Open-Source 3D-Printable Optics Equipment. PLoS ONE 8(3): e59840. This is part of a larger project to reduce the cost of scientific equipment using open-source hardware. Read more here