Book Ring holder 45 deg

Ive always wanted something to help me keeping my book open with only one hand. So I searched the site and I found many similar to this. But not exactly what I needed.

After many prints I decided that I needed something that didn't spread my books wide open, damaging the spines. This 45 deg (aprox) is more natural to what I hold my books anyway and keeps them glued. Also a plain circle for the ring wasn't doing it for me, so I came up with this weird shape

The ring might be too big for smaller hands. but for bony fingers like mine, its even a little tight.