Aircraft Avionics Selector Dial Knob. P/N MS25165-1. Alternate P/Ns 533-051-02, 70-200, 80-018-3G, 99-25165-1, CPA-3851, FNA2562, MIL-K-25049, NAMS25049, SMB282264. NSN: 5355-00-579-2896. It fits 1/4" diameter stem. It was removed from a salvage aircraft.