Features There are 17 calibration weights in this weight set, with 13 different specifications in total In addition to the calibration weights, the set is also equipped with tweezers and a plastic storage box for easy use and storage Our weights are conjoined cylindrical, with raised parts on the upper end, easy to grasp Using No.45 steel material, it has higher strength and resistance to deformation than ordinary steel Suitable for general laboratory, industrial measurement, educational purposes, etc.; the allowable error is -0.003 to +0.003 g Specifications: Permissible Error: +/- 0.003g  Quantity: 1 x 100g,1 x 50g,2 x 20g,1 x 10g, 1 x 5g, 2x2g, 1x 1g, 1x500mg, 2x200mg, 1 x 100mg, 1 x 50mg, 2 x 20mg, 1 x 10mg Color: Silver Material: No.45 steel  Total Set of Weights:211.1g Package included: 1 x Plastic Storage Case  1 x Tweezer 1 x 100g Calibration Weight 1 x 50g Calibration Weight  2 x 20g Calibration Weights  1 x 10g Calibration Weight 1 x 5g Calibration Weight 2 x 2g Calibration Weights 1 x 1g Calibration Weight 1 x 500mgCalibration Weight 2 x 200mg Calibration Weights 1 x 100mg Calibration Weight 1 x 50mg Calibration Weight 2 x 20mg Calibration Weights 1 x 10mg Calibration WeightNote: Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering. Package List