Airbags are supplementary restraint systems that inflate quickly during a crash to prevent drivers and passengers from hitting hard surfaces inside the vehicle. They consist of an airbag module containing a folded nylon airbag and inflator unit, diagnostic and crash sensors, and related electronics. Upon detecting a crash, sensors trigger the inflator unit which produces gas to rapidly inflate the airbag within 0.05 seconds, cushioning the occupant's impact. The airbag then deflates within 0.3 seconds through small pores. Modern airbags now provide enhanced protection to the head, neck and other body areas.