A few months ago, I asked about holsters for my FF STL-V6 and didn’t find any at the time.
I recently got this holster from Intl-Outdoors and it fits fine and protects the light while being carried.
It also fits my TF X9 but with about an inch of unused space at the bottom of the holster. I stuff a lens cleaning rag in it.
Then I needed a sling to carry the holster. The sling hooks to a D ring on the holster.
Here are links to the items I got and use now, both items are well made…
http://www.intl-outdoor.com/large-head-218650-flashlight-holster-p-356.html