Great old, really old, accessory tag & stop light. 9 inches long. 3 inch diameter red glass stop lens. The bottom has a clear glass panel to illuminate your license tag. There is a fitting in the back to lock the fixture into a round rod, perhaps extended up from your tag bracket. The light fixture needs a bulb, perhaps you will retire for 12 volts. Unbelievable condition for something 100 years old!