With the dozens of options out there for attachments, I am sure something is available.
Don't know off hand where to find such a thing, or what it might cost. Looks like a cellphone clip to me, designed to detach with a cell case. That is a little different than what I am doing.
The polymer belt clip I have is pretty tough, and you can easily take it off and put it on again. The belt tunnel is more durable, but not as easy to put on/take off.
I try to design the cases so the mods have easy access, and you don't have to take the case off to use them. Pull them out, vape, put them back.
I can block for most any type of attachment tho, per customer spec.
It was from a old cell phone case, I have searched a bit to find some of them online, I never found any. I think for the billet box, yours would suit me fine, I just wanted to explore what I could do for my provari, I have made this one work for me for a long time, and if it does finally break, I have one more clip I can make another with. It will be a while before I can order one for the BB, but I will.
Thanks
KAS