HANS stands for the Head and Neck Support system, an innovative safety device that has been seen in other codes of motorsport for years, but which became mandatory in Formula One for the first time in 2003.The HANS system consists of a carbon fibre 'collar' worn by the driver around his neck and fitted under the shoulder belts of the safety harness. The helmet is then loosely connected to the collar by three tethers, which allow free movement of the head in normal operation. In the event of a frontal impact the amount of helmet deflection will be controlled by these tethers, while the collar is locked in place by the tightening safety harness.