The P2 easily proves that light output doesn't depend on size and weight alone: This up to 16 lumens strong keychain flashlight measures 102 mm and weighs only 36 g. In other words, less than the battery cap of a large flashlight. It also lasts up to 7 hours and has a lens which separates white and blue light. Just turn the button and the light beam with a blue aureole focuses itself. In other words, we haven't skimped on anything - except weight.