EASY MEASUREMENT: Each blade is laser etched with inches and millimeters for convenient measurements | HIGH-QUALITY BLADES: This dimensional measurement gauge contains 22 hardened, tempered steel blades | USE ON VARIETY OF ITEMS: From machines in your shop to guitars, this gauge test can ensure accurate measurements for the best performances | PROTECTED BY: This valve adjusting feeler gauge is built to last, but if anything happens to it during common use, then it should be covered by the OEMTOOLS Limited Lifetime warranty. See product manual for full warranty conditions and restrictions | EASY TO SWITCH BLADES OUT: To switch blades out of your feeler gauges, simply use the blade protector’s thumb notch for the easiest removal