Spanner Wrench- This spanner wrench is used for adjusting and disassembling Roto-Joints used in all UMI Performance products. Over time if the delrin race inside the Roto-Joint would wear the spanner wrench is used to tighten the adjusting ring applying more pressure to the delrin inside. The spanner wrench is also used to disassemble the Roto-Joint for cleaning, inspection and rebuilding.