I am astonished that no one knows what this item does. As Ann discovered with her diligent research, the address is that of a well known restaurant in Hue, Viet Nam. There were ten of us in a group there dining and when we were leaving, the owner presented each couple with one of these. What great publicity and so cheap.
While Aussie beer bottles, the little ones, or stubbies if you like, can be opened by hand, I needed to open a bottle of Stella (Artois) and so had to search out a tool to remove the cap and at the bottom of a drawer I found the mystery object, a tool just to remove caps from bottles and it does the job very well.