There is no room for error when it comes to precision calibration. It makes all the difference in a scale to provide the most accurate measurements. The Smart Weigh calibration weights are made of top quality carbon steel to ensure the utmost accuracy when it comes to recalibrating any digital scale. A chrome finish gives it a sleek look. Includes a protective cushioned case that keeps the weight firmly in place. The weights can be used for measuring laboratory, commercial, industrial, or educational purposes. Suitable for a digital scale, pocket scale, food scale, jewelry scale, reloading scale, etc. for accurate results. The weights are compact and portable. OIML Class M1: ± 25 mg.