Description:High precision: The allowable error is -0.003 to +0.003g, the function of precision calibration grams, can be used for digital pocket scales, jewelry carat scales, diamond scales, precision balance testing. Steel Plated: These weights are made of sturdy metal with a chrome-plated finish that resists corrosion and can be reused many times. Easy to use: Comes with tweezers for easy weight selection, for calibration weights or metric calibration weights for electronic balances and scales. Widely used: Suitable for general laboratory, commercial, experimental, educational purposes and everyday use. Package : 17 pieces of precision weights, including 1x10mg, 2x20mg, 1x50mg, 1x100mg, 2x200mg, 1x500mg, 1x1g, 2x2g, 1x5g, 1x10g, 2x20g, 1x50g, 1x100g and 1 piece tweezer.