I was fooling around with my new 123 battery extender and I noticed that the tailcap from my Nuwai luxeon light will screw onto the battery extender (although not completely).
A 123 battery will not fit in it with the tailcap screwed in but a CR2 battery fits fine. Using an MN01 I picked up from McGizmo, I was able to put this together:
A 123 battery will not fit in it with the tailcap screwed in but a CR2 battery fits fine. Using an MN01 I picked up from McGizmo, I was able to put this together: