B-Squared GAPSG Non Marring Gap and Step Gauge, Digital Display, Gap Measuring Range: 1.00mm to 25.40mm / 0.0395in. To 1.0000in., Flush Measuring Range: -6.00mm to +25.40mm / -0.2360in. To +1.0000, Resolution 0.01mm / 0.0005in., Accuracy +-0.02mm / 0.001in.