Whether you're reading a map or searching for a trail, the built-in light sensor in the Petzl Tikka® R+ headlamp automatically adjusts beam pattern and light output, leaving your hands free.When you're looking at an object at very close range, such as a map or piece of equipment, the Reactive sensor adjusts the light to a very wide beam with low outputAs you make your way down the trail, the beam widens and adjusts to a medium light output in order to illuminate objects in the pathIf you raise your head to see something in the distance, such as a trail marker or rappel anchor, the beam becomes focused and the light intensity increasesReactive lighting keeps your hands free longer because you don't need to press a button to adjust light output; it also extends battery life by efficiently using powerDownload OS by Petzl software to modify the functionality of your R+ headlamp; you can adjust light intensity, burn time and distance according to an activityCreate custom activity profiles or select from pre-configured profiles such as trail running, mountaineering and hiking; load these onto the R+ and you're ready to goOS by Petzl software is available for download from Petzl at www.petzl.com/OSHeadlamp can also be operated in constant mode, which disables the sensor and gives you standard high, medium and low output settingsLED shines light 2 - 65m and outputs 7 - 170 lumens on high Reactive mode, 2 - 55m and 7 - 130 lumens on medium Reactive and 2 - 40m and 7 - 70 lumens on low Reactive modeIn constant mode, LED throws light 50m and outputs 120 lumens on high, 40m and 80 lumens on medium and 30m and 40 lumens on lowRed LED positioned to the side of the white LED helps preserve your night vision; use the headlamp as a blinking light to increase your chance of being seen in urban environsIntegrated 1,800 mAh lithium-ion battery recharges with the included micro USB cable via any standard USB port; battery charge indicator lets you know when charging is doneBattery recharges in 4.5 hrs. and can be recharged up to 300 times, making the battery life equivalent to that of hundreds of alkaline batteriesBattery provides 3.5 hrs. of use in high Reactive and constant modes and 12 hrs. in low Reactive and constant modesLithium-ion battery can be replaced with a 3 AAA batteries (sold separately) and a battery pack adapter (not included) for use when you can't rechargeComfortable headband is easy to adjust; two-part construction at the back of the head supports the weight of the headlamp during active adventuresTwo independent switches simplify use: one switch for choosing between Reactive and constant lighting, and the other to choose between high, medium and lowLock function helps avoid accidentally turning the headlamp on when it's stashed in your backpackPetzl R+