Harley Davidson Original OEM Delco Remy Voltage Regulator.Part # 74510-47A.Fits 1947 Knucklehead Models.Fits 1948-63 Panhead Models.Fits Hummer Models 1947-59.This is a used regulator of coarse.I was told it was working when removed many years ago.I do not know how to test it to make sure it`s a good one but I will take the unit to a friends shop next week and check it.I see some original paint still on the unit along with some old wiring and scratches,rust,dirt,nicks,etc.(see pics).This one has a lot of patina.The rubber mounts still seem good too.As always,Please look at all pics so you know condition,(see all pics).Good luck bidding.Thanks for looking.