These 12 acrylic buttons were made to resemble shell and they do look realistic.  They are a creamy white color, 2-hole and measure 1-1/8".  They have a slight well on top so the bottom is a little bit curved, not flat.  The angle of the photo makes them look different sized, but they are all the same.  There are 3 sets for sale individually.  Any multiples will ship for the price of 1.