2002 Mercedes SLK 32 AMG Service Light or Flexible Service System (FSS):
Sometimes referred to as the service or oil change light.  The FSS permits a flexible service schedule that is directly related to the operating conditions of the vehicle.  

The symbol (single wrench) or (double wrench) appears in the main odometer display field prior to the next suggested service.

Depending on operating conditions throughout the year, the next service is calculated and displayed in days (clock w/ single wrench)  or distance (single wrench) remaining.

The symbols (single wrench) or (double wrench) indicate the type of service to be performed:

The message is displayed for approximately 10 seconds when turning the key in the steering lock to position 2 or while driving when reaching the service warning threshold. It can be canceled manually by pressing button (1) (refer to image).  

Once the suggested term has passed, the message plus a wrench symbol preceded by a – (minus symbol) blinks for approximately 30 seconds, and a signal sounds every time when turning the key in the steering lock to position 2.

The FSS display can also be called up for approximately 10 seconds, with the display illuminated by pressing button (1) twice within 1 second.

Service A – Oil & Filter Change (typically once a year)
Service B – Oil & Filter Change, Major Filters, Vehicle Inspection, and any other time or milage-based services (typically once every 2 years)