<p>Instantly convert your incandescent  Maglites into a SUPER POWERED LED flashlight! Twelve Cree XT-E LED emitters and the Lumencraft mosfet driver pound out up to 2,000 retina searing lumens (output of the bulbs is based on use of NIHM rechargeable cells). <strong>Alkaline cells will power the bulb up at a reduced output</strong> so are best used as backup). </p><p>This bulb is for use with the voltage of 3 D cells ONLY. 3x NIMH cells are best, or one high drain 3.7 volt li-ion such as a 26650. </p><p><strong>USER INTERFACE:</strong> By default the bulb is set to have 3 levels of brightness, Low, Medium, High. To select the output mode half press the Maglite switch until the light comes on, quickly let off and half press the switch again. Each time you do so the bulb will change output. Once you find the brightness level you want fully "click" the switch into place. The bulb will memorize the last mode used and come on in that mode when you power it back on.  You can see a <strong>video</strong> on how it works by searching Youtube for "Adventure Sport user interface".</p><p><strong>ADDITIONAL FUNCTIONS: </strong>You can also reprogram the bulb to a very wide range of other brightness levels and mode groups. A full set of instructions on this is in the set of pictures above. <br><br><strong>HOW TO INSTALL:</strong> Start by unscrewing and removing the head of your Maglite flashlight. Next remove the factory reflector, bulb retaining ring and bulb from the switch tower (if you have the bi-pin bulb you can press down on the tower to eject the plastic bulb holder). Next remove the bezel and lens from the top of the Maglite head. Insert the 5000 lumen bulb into the head. Place the lens over the dropin and thread the bezel back down until snug. Screw the head back on to the maglite until it is just "snug" onto the body.</p>