Sturdy & : nut and bolt thread checkers are constructed of rugged and material, all are precision machined with hard anodized surfaces, and rust- threaded pins securely fasten into the holes of the identifier. Excellent Recognition: bolt identifier board instantly recognizes 28 different thread sizes, including metric thread sizes from x 0.7 to M14 x 2.0, and fractional thread sizes from #6 - 32 coarse threads to 1/2 - 20 fine threads. It helps you quickly and easily identify different sizes of nuts and bolts. Clear and Laser Scale: bolt size and thread gauge feature laser-etched Inch and Centimeter scales , providing quick, accurate, and user-friendly identification of various thread sizes. Space-saving Design: nut and bolt has two pre-drilled holes, so you can place it on your workbench for use, or easily attach it to a toolbox or mount it . Measuring , the allows you to choose where you want to place it, making it easier to use and more space-efficient. Meet Your Needs: bolt identifier board is an accurate and easy-to-use nut and bolt thread verifier that helps you identify or organize messy screws and nuts in seconds. Ideal for plumbers, handymen, mechanics, auto mechanics, and machinists. Please note: the physical slightly color difference or difference, does not affect the use, please do not mind, thank you! Colour:Black Material:Aluminum Alloy Package Contents: 1 x nut and bolt thread checkers Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.