Summary This is a holder to attach two fiber optic cable to a 8mm smooth rod and allow easy switching between cables for optical experiments. 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 Costs Instructions Print on your favorite open-source 3D printer. The two fiber optic cables are placed within the holder is held in place with a set screw. Use thumb screw from http://www.thingiverse.com/thing:30500 to attach it to an 8mm smooth rod. If you need the base go to http://www.thingiverse.com/thing:28133 Full information here Thanks to Chenlong for the designs. 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