Image 1 of 3 Image 2 of 3 Image 3 of 3 Convex / Concave 18k Gold Band by Satomi Kawakita $726.00 Size: Select Size Concave (size US 5) Convex (size US 5) Quantity: Add To Cart Added! Simply beautiful stacking rings in solid 18K.Convex has a pointed edge all round that is polished and matt all around.Concave is the reverse. Designed by Satomi Kawakita. Simply beautiful stacking rings in solid 18K.Convex has a pointed edge all round that is polished and matt all around.Concave is the reverse. Designed by Satomi Kawakita.