1,Efficient Identification: This screw bolt size and thread gauge is designed to quickly identify 18 different metric and inch nut and bolt sizes, optimizing efficiency. 2,Accurate Length Measurement: This bolt and nut identifier gauge is equipped with side rulers to accurately measure the length of screws, nuts, and tools, providing accurate results and streamlining workflow. 3,Excellent Aluminum Alloy Material: This metric bolt and nut gauge is made of excellent aluminum alloy material, which is sturdy and durable, and allows for high accuracy thread machining to ensure long term durability under various working conditions. 4,Easy To Carry: This bolt size and thread identifier is small in size, light in weight, and features drilled holes and non slip pads for easy wall mounting or bench placement. 5,Wide Application: This nut and bolt thread checker has a wide range of applications and can be used in mechanical engineering, automotive manufacturing, aerospace, construction engineering, etc. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.