The air bag vest is a personal safety device worn by some motorcyclists and horse riders. Airbag vests initially found popularity among equestrian competitors, and airbags have become mandatory in professional motorcycle racing. In 2018, it became compulsory across all classes within the FIM MotoGP World Championship for riders’ race suits to be fitted with airbag systems. In horse riding, the device is worn over a standard padded vest and is automatically inflated by gas released from a carbon dioxide canister when a tether attached to the horse's saddle is extended during a fall.