With the familiar 'QuickClik' system users can, within the 'General' function set, choose Full Power (maximum Lumens): Low Power (up to 113 Lumens: 2-Cell); or Eco Mode - a super power saving mode that yields up to 23 Lumens (2-Cell) with greatly extended run-time.There are three additional function sets - Outdoor; Law Enforcement; and Military - each offering a different set of functions invoked in a different sequence, for quickest access to the functions the particular user prefers.