1 button) 30x16mm Swarovski Art #3093 Rectangle Chessboard Button in Crystal M-foil! 
These are mirror clear, and foil-backed to catch the light. 
"Chessboard" faceting on top. 
 The back is M-foiled, and appears a gunmetal grey. 
There are 2 holes to sew the button onto a garment, or to use as a clasp.
You will receive 1 big, beautiful button.