Feeler gauge set supplied in a fold up case with a tightening screw to prevent loss of individual bladesThe set is supplied with 20 blades, each 3.94 inches in length and is ideal for use on engines and cars and everything in betweenThe blades measure from 0.05mm to 1.00mm in 0.05mm increments enabling multiple combinations for measuring and checking gapsEach blade is constructed from hardened rolled steel, is built to last and the case contains a blade notch for easy blade removalEach blade has sizing information etched into it for quick and easy identification)