I design bags for my own use.
I'm always looking for ways of creating a new design for certain functions or finding new ways to tweak and enhance those bags I've already made.
This is exactly what I've done with the H&K wallet. It now may be carried as a sling.
Carry it in your purse, and you can stow the sling away in its own pocket, which I've added to the back of my current design.
~Also carry it as a wristlet.