Mil-Tec's white 6" light stick. This light stick, which produces strong white light for a shorter period of time, has a bright light "burn time" of about 30 minutes, after which the stick produces a dimmer light for about 90 minutes. This light stick is well suited for example as an emergency and attention light. The stick also shines well, for example, underwater.
The stick is a plastic tube about 6" / 15cm long and about 10mm thick, with a loop at the end that can be tied to anything. It is activated by bending it so that the containers inside break. The outer shell of the stick cannot be broken - at least not without proper tools, effort and will. The chemicals inside are non-toxic.
The creation of glow sticks is primarily due to the US military. The ultimate purpose of glow sticks is to produce completely safe light without a power source. The light from a glow stick is caused by a chemical reaction that produces only light, not heat. They are disposable and do not require a battery or anything else. The light is not terribly bright, but it is suitable for reading maps, rummaging through a backpack, etc. Glow sticks are particularly handy for marking all kinds of things - objects, places or tent ropes, for example.