Features: Accurate Calibration: This external micrometer calibration rod is an essential tool to ensure the accuracy of your caliper measurements. Durable Material: Produced of quality metal, this calibration rod is sturdy- and long-lasting, providing reliable support for your measuring need For Professionals and DIYers: Whether you're a professional machinist or a DIY enthusiasts, this calibration rod is perfect for anyone who need precise measurements for their projects. 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. Specifications: Material: metal Standard: 50mm/25mm/75mm/100mm/125mm/150mm/175mm/200mm/225mm/250mm/275mm(optional) Note: The micrometer 0-25mm does not require a measuring rod. The micrometer 25-50mm uses a 25mm measuring rod, 50-75mm uses a 50mm measuring rod, and 75-100mm uses a 75mm measuring rod. Note: Please allow 1 to 3cm error due to manual measurement, please make sure you do not mind before you bid, Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1xCalibration Rod