Calibration weights 1.OIML mass tolerances,OIML R 1111 international standard. 2.E1,E2,F1,F2,M1,Class 3.High accuracy OIML class M1 ... /50g/100g/200g/500g/1000g; 1kg/2kg/5kg/10kg/20kg High Quality Calibrated Weights, Balance Calibration Weights, Precision Weights, Calibrated Weigh,calibration weight set masses