ITEM NAME:50+75+100mm Outside Micrometer Caliper Standard Measuring Rod Bar Description: Outside Micrometer Standard Calibration Measuring Rod Bar Material: plastic; Diameter:Approx. 7mm Range: Approx. 50mm/2 inch; 75mm/3 inch; 100mm/4 inch for your choice Accuracy:Â ±0.001mm Widely use for micrometer, micrometer caliper, microcallipers. Package Includes: 3 piece Micrometer Standard Rod 50mm+75mm+100mm.Range: Approx. Accuracy:Â ±0.001mm.