Made from high quality carbon steel with hardened and finely polished points. Firm joint calipers use friction at the joint to hold the legs unmoving. Outside calipers measure thicknesses and outside diameters of objects. Inside calipers measure hole diameters and distances between surfaces. Lightweight and easy to handle calipers,suit for pottery , clay art and ceramic crafts measuring and check. Specification: Material: Stainless Steel Color: Silver Size Chart: Open Size (L): Approx. 49 cm / 19.29 inch,Total Size (L): Approx. 25.5 cm / 10.04 inch Open Size (L): Approx. 39 cm / 15.35 inch,Total Size (L): Approx. 20.5 cm / 8.07 inch Open Size (L): Approx. 36 cm / 14.17 inch,Total Size (L): Approx. 20.5 cm / 8.07 inch Open Size (L): Approx. 47 cm / 18.50 inch,Total Size (L): Approx. 26 cm / 10.24 inch Open Size (L): Approx. 28 cm / 11.02 inch,Total Size (L): Approx. 15.7 cm / 6.18 inch Open Size (L): Approx. 18.5 cm / 7.28 inch,Total Size (L): Approx. 10.6 cm / 4.17 inch Open Size (L): Approx. 20 cm / 7.87 inch,Total Size (L): Approx. 11 cm / 4.33 inch Package Includes: 1 Piece Pottery Clay Measure Tool(3 Pack) Note: Due to the difference between different monitors, the picture may not reflect the actual color of the item. Due to manual measurement, there may be 1-2mm error in size.