Mercedes 1248205110 SRS Crash Sensor.  This part is often mistakenly called the SRS module, but there is no SRS module on these early SRS cars, just this crash sensor located behind the dashboard, which is a one-time-use and must be replaced after each airbag deployment.  This particular one was pulled from a 1987 Mercedes 300D Turbo, and is the type with the shorter 44 inch cable.  This type does not fit my 1986 560SL, which needs the longer cable.  Please check yours before ordering.