Measure your ring size accurately and with ease using this quality metal finger gauge (Japanese sizes 1-30 in one size increments), smoothed and chromed for maximum comfort and durability. The size stamped on the rings are Japanese sizes, please see the table below for equivalent world wide sizes.With this calibrated metal ring sizer or finger gauge in Japanese sizes of 1-30, you can accurately fabricate PMC silver rings to their correct sizes.Simply select the ring that fits the finger you wish to measure to find the optimal size.Quality made in Japan. InchesMillimetersInchesMillimetersUnited StatesCanadaUnited KingdomIrelandAustraliaNew ZealandIndiaChinaJapanSouth AmericaItalySpainNetherlandsSwitzerland0.45811.631.4436.50   0.46611.841.4637.2¼   0.47412.041.4937.8½A  0.48212.241.5138.5¾A½  0.49012.451.5439.11B1 0.49812.651.5639.71¼B½  0.50612.851.5940.41½C 0.50.51413.061.6141.01¾C½ 10.52213.261.6441.72D21.750.53013.461.6742.32¼D½ 2.250.53813.671.6942.92½E330.54613.871.7243.62¾E½ 3.50.55414.071.7444.23F44.250.56214.271.7744.83¼F½54.750.57014.481.7945.53½G 5.50.57814.681.8246.13¾G½660.58614.881.8446.84H76.750.59415.091.8747.44¼H½ 7.50.60215.291.8948.04½I880.61015.491.9248.7