I have two: EM1250 C8139-8 EM1220 C8138-4 They're gray, ceramic, with nice bell covers. Dated 1966 and 1967. I have found very little info from Googling. I only found one statement that the EM1220 might be a 100watt speaker (?). I would have guessed 20 myself, but what do I know? I'm also supposing the dash numbers are impedance ratings?