Fits all 123 Chassis from 1977-1985, gas and diesel models with automatic transmission. There is a small light bulb that fits down in your shifter just below the indicator cover. At night it lights up the indicator so you can see what gear you are in. Many times this bulb is burned out, and makes it difficult to shift at night! Sorry no instructions included.
ALSO FITS W116 CHASSIS
123 Automatic Shift Indicator Light Bulb