Practical headlamp works with 1 included battery or 3 batteries, which is essential in case electricity is not available. Another practical aspect is that the lamp can be easily removed from the elastic headband to be attached to a metal part, as it is equipped with a magnet. It also comes with an adhesive mount to attach the lamp to a non-metallic helmet. For me, the number of lumens is sufficient because the light beam is wide and allows you to go about your daily activities.