This set of 12 Class M1 calibration weights ranges from 1g to 500g. The weights are presented in a lined aluminium box complete with forceps and white cotton glove.It contains the following weights:1 x 1g 2 x 2g 1 x 5g 1 x 10g 2 x 20g 1 x 50g 1 x 100g 2 x 200g and1 x 500g.OIML weight sets are a complete set of test weight that can meet the requirements for testing to OIML standards. M1 weights offer the lowest accuracy but are more affordable and are ideal for lower cost items such as compact balances and bench scales.