Set contains 12 different polystyrene standards with Mp ~266, Mp ~374, Mp~1100, Mp~1920, Mp~2950, Mp ~4870, Mp ~7200, Mp~10400, Mp ~15700, Mp ~19600, Mp ~34800, Mp ~67500; always 4 standards are lyophilised in a 1,5ml vial (yellow, blue or black); for 1 complete calibration use one of each of the yellow, blue and black vials; 1 set contains 30 vials for 10 complete calibrations.