I just got Willie Hunt's custom insert system for 2 D cell Mag flashlights. This allows one to convert a 2 D cell Mag flaslight into one powered by eight AA cells (I used lithium batteries myself, tho alkaline may be used) which drive a Willie LVR, that in turn drives a 3.6 volt .8 watt high efficiency xenon bulb (supplied by Willie as part of the kit). I stumbled accross it HERE I was thinking about adding 2 Lithium D-cells and a Carley Xenon Star lamp for a 5 or 6 cell maglite, but this was a more practical and less expensive modification of the old Maglite. I'll let you know how it works.