Caliper and Height Gauge Checker Designed for the Calibration of all kinds of Calipers & Height Gauges Hardened and ground steel blocks. Range: 300/600/1000 mm. Accuracy:300mm 0.003mm. Accuracy:600mm 0.005mm. Accuracy:1000mm 0.007mm. Accuracy:12in. 0.00012in. Accuracy:24in. 0.00020in. Accuracy:40in. 0.00028in.