Dolan-Jenner Dual Branch Gooseneck Fiber Optic Light Guide Cable for Illuminator  2-way Split

I hooked it up to a light source and it works great but there is a circuit board that looks like it is wired to one side and so no light shines through that side.  I don't know what this board is for or what this was used for.   I only have the accuracy of a measuring tape but the diameter of threaded end looks to me to be about 15/16" in diameter.    The small end is about 5/16" in diameter.  The length looks to me to be about 25".  The circuit board has the number 98-169-001 REV. 1 on it.

S499-38

fdk 80602198