... Calibration weights 1.OIML mass tolerances,OIML R 1111 international standard. 2.E1,E2,F1,F2,M1,Class 3.High accuracy OIML class M1, ... F2, F1, E2, E1 Capacity: 1mg-20kg ... ; 1kg/2kg/5kg/10kg/20kg High Quality Calibrated Weights, Balance Calibration Weights, Precision Weights, Calibrated Weigh,calibration weight set masses