If you are out in the wild you need your flashlight to last, and the multi-level dimmer switch allows you to choose exactly how much light you want, so that there is no unnecessary battery waste. The modes offered by the dimmer switch in order of most to least power used are Turbo, High, Medium, Low, and Strobe. This flashlight's digitally regulated output makes each setting consistent, so that you can be sure of what you are in for. To help to ensure that you get the most out of the Fenix TK15, its lens is covered with anti-reflective coating, so that its light is uninhibited.