FC11C uses Buck circuit (FC11C) delivers a maximum output of 1200 lumens . Its side switch controls all functions: power on/off, battery indicator, output level and change of mode groups. It also provides an improved, user friendly interface and simple one-hand operation. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.