If you are looking for a lamp that you can wear on the helmet or on the head, helmet lamps (also known as headlamps) are the perfect choice. Depending on the purpose you should choose a different strong lighting. Depending on the manufacturer, the luminous intensity is given in lumens or lux.
According to StVZO, this type of lighting is not allowed in Germany on public streets or ground. Accordingly, they must never be used in traffic. They are only allowed at official sports events, on private grounds or in places where the rules of the StVZO do not apply. If you want to participate in the traffic, you must rely on a StVZO-approved lighting. If you want to use helmet or headlamps outside of Germany, please inquire about the legal regulations in force in each country.