Please help with ID buttons make of nickel with long loop back

[connierocket]

1. This set of buttons are made of nickel. I had them tested for metal content. I am interested to know  what they were used for because of the long loop back. Has anyone seen anything like it?  Thank you!

[silvergirl03]

Sorry I have not seen anything like them but I would guess the long shanks are because the button is so deep and to fit the item.