Accurate Calibration: This external micrometer calibration rod is an essential tool to the accuracy of your caliper measurements For Professionals and DIYers: Whether you ' re a professional machinist or a enthusiasts, this calibration rod is perfect for anyone who need measurements for their projects : Produced of metal, this calibration rod is sturdy and long-lasting, providing for your measuring need All-rounded Usage: Use this calibration rod with calipers to measure a wide ranges of objects, from small parts to larger component Simple to Use: Simply attach this calibration rod to your caliper and adjust until the readingmatch the marks on the rod It is simple to use and saves you and frustration, Manufacturer: YPBEW