Tube size misrepresented - Fenix TK Series LED Flashlight

I like the light a lot. Operation is simple with just three power levels, then the strobe, with no memory circuit. There doesn't seem to be anything cheap about it.
I wanted a 1" tube but this tube is smaller. The end cap is 1". I didn't want to mount at the battery cap so I had to buy the "Fenix ALG-01 Tactical Flashlight Ring" for around $10. That's not so bad but the mount is big & heavy. Hopefully the durability will justify all that bulk.
The light is so nice, I want to carry this on in the holster but then I'd have to buy an Inforce to mount...