Features: AluminumAlloy material: Both the nut and bolt thread gauges adopt AluminumAlloy material, will not rusts, is corrosion-resistant, and have a service life of many year. Nut and bolt thread inspector: 44pieces including 23inch and 21 metric part, 26pieces including 14inch and 12 metric part, including male/female nut and bolt size inspection table. Used for quick and accurate identification and verification of nut and bolt dimension. Thread measuring instrument: includes both inch and metric sizes: from M3x0.5 to M24x3.0 in metric, from 6-32 to 1-12inch, and a complete set of nut and bolt measuring tool. Nut and bolt measuring tools: We come with plastic case and highs-density sponges to store these nut, making them neat and ordered. The specifications is clearly indicated on the packagings box, and the nut is clear for easy and quick identification. The case is easy to store and carry. Specifications: Material:AluminumAlloy Quantity:26Pcs,44Pcs Package Includes: 1Set Nut and Bolt Thread Checker note: Please allow 1mm errors due to manual measurement. Due to the differences between different monitors, the picture may not reflect the actual color.