Features: 1Accuracy: 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. 2Black 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. 3Silver 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. 4Nut And Bolt Thread Checker: With 44 male and female gaugesincluded 23 inch and 21 metric sizesour product is the ideal solution to all your nut and bolt checking needs. 5Material: Robust zinc alloy construction. Our threaded detector sets are made of zinc alloy and are durable with frequent use. 6Time 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 xNutandBoltThreadChecker