Mercedes-Benz SL 320 Operator's Manual page 42

Unfastening of Seat Belts
Push in the red button (3) in the belt
buckle (2).
Allow the retractor to completely
rewind the seat belt by guiding the
latch plate (1).
Operation:
The inertia reel stops the belt from
unwinding during sudden vehicle stops
or when quickly pulling on the belt.
The locking function of the reel may
be checked by quickly pulling on the
belt.
The emergency tensioning retract ors
tighten the fastened seat belts during
frontal and front-angled impacts
exceeding the first threshold of the
SRS (see Index).
Note:
For cleaning and care of the seat belts,
see Upholstery in Index.
42