Motorcycle helmets are simply the most important item for a rider's physical safety concerns. When purchased and worn correctly, motorcycle helmets can be the only safety item that will provide the rider the necessary protection from suffering a possibly debilitating and sometimes life threatening head injury. With the exception of the states of Iowa, Illinois, New Hampshire and Colorado, the remaining states all require some or all riders to wear motorcycle helmets. Some manufacturers of motorcycle helmets include Arai, Bell, HJC, Icon, KBC, Nolan, Scorpion, Shark, Shoei, Sparks, Suomy and Vega. Motorcycle helmets are rated/approved by either the Snell or federal DOT agencies.