Light stick 5x1x1 cm, which is charged by daylight and then at night glows in color (fluorescent). It is used to mark objects on the campground (tent zippers, stretched cords, backpacks, bags, ...), as an identification tag for keys and other objects, for night fishing, and in general for all cases when I want to highlight something in the dark. It glows even underwater. The glow in the dark time depends on the charge, but can be up to 12 hours. The Nitestik is also rechargeable with artificial light, or even with light from a fire, etc.