Here we have some new, high quality, Italian designer, antique silver finish, metal buttons - shank loop style that come in lots of 8, 5 and 3 sizes:    13/16=20mm, 11/16 = 17mm, and  5/8 = 15mm. 

Buttons are made in Italy.

Pick a size -  there are lots of 3, 5 and 8.  Great for blazers, jackets, blouses, suits.     

Check out other buttons listed.