I have a couple of the 2D LED Maglights that work well, and you can focus them...pic is a modification from the 2004 power outage, when I was habitually misplacing it... clips to key snap
I've become a fan of the SolarForce light modules and tubes... my current flame thrower is the M3 head on a 2x123 L2 body... a +1 extension is in the mail... I have a Malkoff conversion in my old Surefire 6P with my pistol, but XM L2 U2 SolarForce modules in the rest of the G2s and L2Ms and L2Ns