The standard-fitted windowbags on the S-Class consist of nine chambers with a total volume of approximately 12 litres per bag. Within 25 milliseconds of a side impact the windowbag, which is approximately 2000 millimetres long, inflates like a curtain between the front and rear roof pillars. The inflated bag provides a large protective surface at head level for both the front and rear passenger, regardless of passenger stature and seat position.

Under normal conditions, the windowbags are concealed behind the interior trim (roof frame, A-pillars and C-pillars). In the event of an accident, they force this trim inwards as they deploy. The windowbags are also activated, together with the belt tensioners, if the rollover sensor detects a rollover of a certain type.