3 7/8 X 4 3/8 composite signal with the standard size pinhole. Reddish in color. No manufacture marking. I don't see many of these but that doesn't mean a thing. Could be trolley application but you would think it would have a 1 3/8 pinhole. $20.00 + shipping. First email that says' "I'll take it.". No PayPal. Email with questions.