One of the larger lights that I've made in titanium--24mm x 113mm--this light uses a McClicky and has an 18650 battery:
I'm not sure why I'm so fascinated with copying Mondrian--these designs are a b*tch to make--each line takes four passes to get to the proper depth. It literally tied up my lathe for days on end--it's not as though you can just step up and do all the lines at once--it requires extreme concentration to do this manually. In fact, the total number of passes came to 264.
Well, extreme concentration is needed if you want to cut them perfectly. And, as always, I'm never perfect, nor is this light--it actually has one tiny mistake. But I won't tell the buyer where it is.
Final pics can be seen in post #18.