I have a 6D with the extension (8 D), and you can buy an aftermarket 10 watt cree bulb that makes it brighter than most surefires.I still have one, I do not know if you remember a kit they sold. It contained a 4 D cell light with a 2 D cell extender to make the 4 into a six. Well guess what happened people would add the 2 Cell extender to a 6 cell light and make an 8 cell. The kit was discontinued shortly after introduction.
I have one in each cell count still, hard to believe these were the best light available at one time. My phone is brighter than they were.
https://www.dracoproducts.net/produ...ite®-5-6-7-8-cell-light-5-30v-replace-krypton