GSG Micrometer & Caliper Calibration Kit These micrometer masters are available in both English and Metric versions, and are ideal for ensuring your micrometers and calipers are always giving you the right results. Each unit is case hardened, stabilized and ground. All diameters are chrome plated for longevity and corrosion resistance and ground to a tolerance of ±.0001 or ± .0025mm. Features include... 12 Measuring / Setting Steps 1" Steps for 1-12" 25mm Steps for 25mm-300mm Accuracy: +0.0001" / +0.0025mm Includes Wood Storage Case Lead Times are about 4-6 weeks ARO. Select Inch / Metric from Pulldown Menu