Mercedes-Benz 500 SEC Operator's Manual page 27

Rear Passenger Compartment
Adjustable Air Outlet
Slide switch (1) up to open outlet for
fresh/cooled air only.
Activated Charcoal Filter
1 Switch on
2 Switch off
An activated charcoal filter markedly
reduces bad odors and removes
pollutants from the air entering the
passenger compartment.
When pressing button
the filter is also switched off.
Note:
The activated charcoal filter should be
switched off when windows fog up on
the inside, or if the passenger
compartment needs to be quickly
heated up or cooled down.
or ,
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