Very bright multi-function light which has a carabineer for clipping it to bags etc., so it is always at hand. It uses COB (Chips on Board) technology to produce much more light intensity than conventional lights but draws a lot less current which dramatically increases battery life. Multiple LED diode chips are bonded directly to a circuit board (which is usually yellow) to form an incredibly bright light module. Other features include a metric ruler on one side, a spring loaded tape measure and a bottle opener. It laser engraves to an oxidised white finish and the light uses one button cell battery which is included.