Yellow Mountain Imports 20 Spare Yunzi Go Stones, Double Convex, 9.2 Millimeters (Size 33) If you have lost or broken a few size 33, double convex go stones, this set of 10 black and 10 white stones will bring your set back to full count; each spare is a 9.2 millimeter (Size 33) double convex stone; each stone measures 9.2 millimeters tall and 21.5 millimeters wide (approximately 0.36 x 0.85 inches) The stones will actually look nicer over time as they absorb moisture and natural oils from your fingertips; Yunzi stones have been made for almost a thousand years in the same area of Yunnan province in southern China The texture, symmetry, and precision of these spare Yunzi stones are superior 30 day return policy; here, at Yellow Mountain Imports, we want you to be satisfied with your purchase; you are backed by our 30 day no questions asked money back guarantee so you can buy with confidence Stone: 0.36 x 0.85 inches (9.2 x 21.5 millimeters) approximately This set of 20 spare Go stones are genuine Yunzi stones that are 9.2 millimeters thick (Size 33) and double convex (fully rounded on both sides). The balance and deeply rich color of these spare Yunzi stones are instantly noticeable. As the stones absorb moisture and natural oils from your fingertips, they will actually look nicer over time.