Made of durable aluminum alloy, these flashlights are of good quality and can serve you for a long time. Battery are included and replaceable.Its operation is very simple,pull the bottom part out of the colored plastic cover and hold the inner aluminum body tight, then unscrew it to take out the small plastic slice above the battery for it to work. It is used in a variety of situations,for example,outdoor activities, hiking, camping, cycling, night walking, ect.