26 Blades Steel Feeler Gauge Dual Marked Metric and Imperial Gap Measuring Tool. Durable for Use - Constructed from hardened tempered steel with a lube oil coating to prevent pitting and corrosion. Wide Application - Suitable for designers, engineers, mechanics to measure the thickness of tappet clearances, spark plugs gaps, bearing clearances, piston ring gaps and other hard to reach places. Measuring Range - 0.0015 inch/ 0.038 mm to 0.025 inch/ 0.365 mm. Metric sizes (mm): 0.04 mm, 0.05 mm, 0.06 mm, 0.08 mm, 0.10 mm, 0.13 mm, 0.15 mm, 0.18 mm, 0.20 mm, 0.23 mm, 0.25 mm, 0.28 mm, 0.30 mm, 0.330 mm, 0.35 mm, 0.38 mm, 0.40 mm, 0.43 mm, 0.48 mm, 0.45 mm, 0.50 mm, 0.53 mm, 0.55 mm, 0.58 mm, 0.60 mm, 0.63 mm Inch sizes: 0.0015, 0.002, 0.0025, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.010, 0.011, 0.012, 0.013, 0.014, 0.015, 0.016, 0.017, 0.018, 0.019, 0.020, 0.021, 0.022, 0.023, 0.024, 0.025 inch