Set of 12 buttons (7 large, 5 small) Thank you for viewing. The back side is blue. Not sold separately. ■Size Large: Diameter: approx. 10mm Thickness: approx. 2mm Small: Diameter: approx. 9mm Thickness: approx. 2mm (※Please note that there may be slight variations due to individual measurements.) ■Note: We cannot accept cancellations after the item has been shipped. Please refrain from purchasing if you are overly concerned about details or if you are easily worried about oversights. Thank you for your understanding that these are used items. Thank you for your consideration (^-^)