1、Quick Size Identification: 28 hole nut and bolt thread checker with English and centimeter scales allows you to easily identify 28 different sizes of nuts and bolts. 2、Robust Material: Made of 6061 aluminum alloy with hard anodized surface, the thread checker is sturdy and rust resistant, ensuring long lasting durability. 3、Convenient Installation: Equipped with 3 pre drilled mounting holes for easy wall hanging or toolbox attachment, providing easy access when needed. 4、Clear Laser Scales: The bolt and nut gauge features laser etched inch and centimeter scales for quick and easy size comparison, helping you identify sizes accurately. 5、Versatile Tool: Perfect for professional mechanics or enthusiasts, this thread checker board helps you quickly and accurately compare exact sizes without the confusion of coil type identifiers.