Wow! It has been two years since I last posted or read posts here. I am really glad to see some familiar BLF members are still around here and testing/modding flashlight and LED.
Recently I actively reading about flashlight again. So I start buying flashlight stuffs again. So I extended my TKs’ runtime, this was something I wanted to do but I didn’t do. Not sure why I am obsessed with it though I don’t need the extended runtime at all. Maybe I like my flashlight to be heavy . The seller who sold me the battery tube told me Fenix seems to have discontinued this battery tube. I do think it is good idea to be able to extend runtime without need to swap batteries, sure it will be useful for some people.
Below are my TK75 and TK61 with battery tube, and also my TK70.