I had 3 mag lite flashlights with the original bulbs. I have a 2 cell, 3 cell and a 4 cell maglite.  After seeing the power of the new led flashlights out there I was ready to retire my trusty maglites.  A year ago I replaced the original bulbs in all three flashlights with these led bulbs. The increased light and extended battery life is excellent.  I don't understand the reviews that complain about the light quality and the reflectors not working.  They work great in all three of my maglites.