[Accurate Nut and Bolt Checker]: The was designed to make your job easier and improve efficiency, being a fast and simple way of verifying the thread of your bolts and nuts. An excellent choice for construction, engineering, technical schools and more! [Heavy Duty Construction]: This standard and metric thread gauge is made using premium Carbon Steel, a rustproof material which doesn 't bend or break, designed to withstand the test of time. [Wire Loop Assembly]: This screw size and thread gauge features a smart wire loop design which makes it easy to store or hang, at the same time preventing losing the smaller pieces. [Engraved Measurements]: Say goodbye to the hassle and guesswork that consumes your time, with the thread gauge SAE and metric, featuring permanently engraved thread sizes for easy and accurate identification. [Size Range]: Metric sizes included: M3x0.5, M4x0.7, M5x0.8, M6x1.0, M7x1.0, M8x1.0, M8x1.25, M10x1.0, M10x1.25, M10x1.5, M12x1.25, M12x1.5, M12x1.75, M14x1.5, M14x2.0, M16x1.5, M16x2.0, M20x1.5, M20x2.5, M24x2.0, M24x3.0. Inch sizes included: 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. Colour:Silver & Black Material:carbon steel Package Contents: 44 * Nut and Bolt Checker Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.