Baker bore gauges allow rapid and accurate checking of bores for size, Ovality and taper as also wear of bores like Engine Cylinder bores etc. in the workshop or inspection room. All bore gauges operate on the proven principle of two diametrically opposite measuring points, one fixed and one moving with a spring loaded centralising shoe. To check the actual size of bore, the gauge must be set to size with a bore master (Master Setting Ring) of known diameter which is close to the size to be measured. Inserted into the bore, it is necessary to "rock" the gauge slowly to locate its measuring axis to the bore shown by the point of reversal of the indicator hand. The reading at that point is the deviation from set normal size. A range of interchangeable extension rods allows a single instrument to cover wide range of bore sizes.Baker Dial Bore Gauge, Model no. K703, Range: 18-50mm, Resolution:0.01mm, Dial Reading: 0-50-0, Units/Pkg: 1, Warranty: As per manufacturer's warranty policy.