Wasn't fond of the strange big grey buttons, found these on Aliexpress for under $4.00
The ring is actually metal and they are quite nice quality. The small top button fit perfectly, however the two larger buttons were a loose fit, I remedied this with a tiny strip of two sided tape inserted into one channel on each button.
I think it looks much better now
Oh here's the link: http://s.click.aliexpress.com/e/ceEkJgaM