Potentiometer with 500kOhm resistor, logarithmic characteristic and 9, 5mm standard shaft of WSC Partsland the Split Shaft version.
I know all pots have a 20% tolerance but I've never tested any CTS, Bourns or Alpha pots that had anything more than 4/5%.
When I measured these on my multimeter they varied from 406 to 587k. As such unusable as a set of pots.