How the head-and-neck restraint system works

As part of its continuing safety initative, NASCAR became the world's first major auto racing sanctioning body to mandate the use of an approved head-and-neck restraint by all drivers on every type of race circuit, beginning with the 2002.

The HANS Device helps to reduce extreme head motion during accidents and sudden stops. The device is required for use in NASCAR's three national series -- the NASCAR Nextel Cup series, NASCAR Busch series, NASCAR Craftsman truck series -- as well as its regional touring series, How the HANS Device works is illustrated below.

Source: NASCAR