Seatbelt Pre-tensioners and Force Limiters

seatbelt pre-tensioners, which take the slack out of seatbelts quickly and automatically under heavy braking or in a frontal crash, are standard in most vehicles. Pretensioners help ensure that occupants get the best possible protection from their seat belts. Check to make sure the vehicle you are buying has them.

When pretensioners work, they can make the belt quite taut, possibly leading to chest injuries in the event of a crash. That's where seatbelt force limiters come into play. Force limiters let a little bit of slack back out of the belt. They are designed to work with the airbag to help spread frontal crash forces across the occupant's body, thus reducing the risk of injury.

Force Limiter Diagram