Mercedes-Benz 2006 E -Class Wagon Operator's Manual page 205

Controls in detail
Dual-zone automatic climate control (USA only)
1 Temperature control, left
2 Front defroster
3 Increase air volume
4 Air distribution
5 Rear window defroster
204
6 Temperature control, right
7 AC cooling on/off
8 Air distribution display
9 Climate control on/off
a Air volume display
b Decrease air volume
c Air recirculation
d Air distribution and air volume
(automatic, manual)