With lock clamps Measuring surface have hard alloy head Smooth chrome plated surface are clear calibration

With lock clampsMeasuring surface have hard alloy headSmooth chrome plated surface are clear calibrationRatchet locking devices or friction casing can ensure accuracy 

Order No                          Range          Resolution           Accuracy5204-25                          0-25mm            0.01mm         ±0.004mm5204-50                         25-50mm           0.01mm         ±0.004mm