This precision calibrated True Ring Sizing Set (3mm) offers consistent, dependable measuring when sizing rings time after time. The high quality and the polished, professional look will impress your customers on the other side of the counter while reducing costly, extensive errors when measuring the size needed and the end result being totally different. Sold as a complete set with matching aluminum mandrel.   Sizes 1-16 in half sizes and sizes 4 up through and including 11 are in quarter sizes.