Excellent Quality: The bolt and nut Identifier gauge is crafted from CNC-machined anodized aluminum alloy and hardness SUS304 stainless steel thread, for maximum thread strength and ultimate precision. with a protective anodized finish laser etched markings wont fade or get scratched off. Laser Etched Dual Scale - Our bolt size and thread gauge features durable laser etched inch and centimeter sized edges, allowing for fast, accurate, and user-friendly identification of various thread sizes. Wide-volume size detection-Our nuts and bolt thread detectors can immediately identify 28 different sizes, including the public thread size of M4 x 0.7 to M14 x 2.0, and 6-32 fine to 1/2-20 fine English threaded threads Essence 28 SIZE Nut and Bolt Identification Tool Ruler With Inches And Centimeters On Both Sides Convenient and essential - very suitable for various purposes, screw gauges can be effortlessly installed on walls or tool boxes. With its reserved installation holes, it is an essential tool for professionals and DIY enthusiasts. Colour:red Material:Aluminum alloy Size: 50 x 10 x 2.5cm Package Contents: 1 x thread check