Rules protecting riders have improved as well. Riders are now required to wear a safety vest (body protector) during cross-country, as well as an ASTM/SEI or ISO approved equestrian helmet equipped with a retention harness, which must be fastened while on the horse. Eventing was one of the first sports to require the use of a helmet with harness when jumping. As of 2010, more riders were wearing air bag vests, which automatically inflate if a rider falls off the horse.