I picked this up from Tim(Negotiable) at the Sturgis Swap Meet. It's the 1/4 speed oil pump breather for an XLR, KR and KRTT. For prolonged high speed, high rpm race applications.
I don't have the pinion/bevel gear that goes with it. It will be larger (more teeth) than the standard gear - maybe you have one? Check your spare parts. Thanks !