I still have my TW4 and play lego lights once in a while. The folks at the late tactical wearhouse made sure each L4 head would work with just one 123 cell before shipping them out to flashaholics. I really hope the extra goodies he sent out wasn't the straw that broke the camels back. Even though there are many more lights with much higher lumens. I wear the surefire Tee shirts quite a bit and the tactical (winkwink) pens are in my franklin planner and one on my dopp kit for my many stays in the local VA hospital.