Belt tensioners

As a rule, the seat belt will not be sitting completely tight around the body: This seat belt slack makes sure that the occupants have adequate comfort of movement.

To prevent the negative effect that this loose belt can have, the pyrotechnic seat-belt tensioner will pull the belt buckle down by several centimeters in the event of a frontal or rear-end collision. This pulls the seat belt tight into the occupant's shoulder and pelvis.