Feature:1. Accuracy: Upgrade dual sides printing size. Inch and Metric thread checker is an accurate and easy to use nut and thread identifier. Thread checkers are particularly suited to distinguish between similar inch and metric threads.2. Black 21 Metric Sizes: M3x0.5, M4x0.7, M5x0.8, M6x1.0, M7x1.0, M8x1.0, M8X0.25, M10X0.25, M10x1.5, M12x1.5, M12X1.5, M12X1.5, M14x2.0, M16 x1.5, M16x2.0, M20x1.5, M20x2.5, M24x2.0, M24x3.0.3. Silver 23 Inch Sizes: 632, 640, 832, 1024, 1032, 1/420, 1/428, 5/1618, 5/1624, 3/816, 3/824, 7/1614, 7/1620, 1/213, 1/220, 9/1612, 9/1618, 5/8 11, 5/818, 3/410, 3/416, 18, 112.4. Nut And Bolt Thread Checker: With 44 male and female gauges,included 23 inch and 21 metric sizes,our product is the ideal solution to all your nut and bolt checking needs.5. Material: Robust zinc alloy construction. Our threaded detector sets are made of zinc alloy and are durable with frequent use.6. Time Saving And Convenient: Our nut and bolt thread checker is designed to enhance your efficiency, save time, and eliminate guesswork.Specification:Item Type: Thread CheckerMaterial: Zinc AlloyWeight: Approx. 963g / 34ozBlack 21 Metric Sizes: M3x0.5, M4x0.7, M5x0.8, M6x1.0, M7x1.0, M8x1.0, M8X0.25, M10X0.25, M10x1.5, M12x1.5, M12X1.5, M12X1.5, M14x2.0, M16 x1.5, M16x2.0, M20x1.5, M20x2.5, M24x2.0, M24x3.0Silver 23 Inch Sizes: 6-32, 6-40, 8-32, 10-24, 10-32, 1/4-20, 1/4-28, 5/16-18, 5/16-24, 3/8-16, 3/8-24, 7/16-14, 7/16-20, 1/2-13, 1/2-20, 9/16-12, 9/16-18, 5/8 -11, 5/8-18, 3/4-10, 3/4-16, 1-8, 1-12.Package List:44 xNut and Bolt Thread Checker