MEASURE GAPS: Use this ABN Feeler Gauge when you need to quickly and easily measure gap widths | VARIOUS APPLICATIONS: Use on anything from guitars to engines and everything in between; Metric and SAE standard sizes are included (millimeters and inches) | BUILT TO LAST: Constructed from hardened tempered steel with a lube oil coating to prevent pitting and corrosion; Each blade has sizes laser etched for easy identification; Blades are bound within a blade protector to prevent loss of individual blades; Tool contains a blade notch for easy blade removal | METRIC: Includes metric sizes .508, .127, .152, .178, .203, .229, .254, .279, .305, .330, .356, .381, .406, .432, .457, and .483 mm | STANDARD SAE: Includes inch sizes .020, .005, .006, .007, .008, .009, .010, .011, .012, .013, .014, .015, .016, .017, .018, and .019 Inches