Hinged polypropylene box with snap-tight closure contains the following masses (tolerances): 1 G (±5 mg), two 2 G (±5 mg), 5 G (±10 mg), 10 G (±20 mg), two 20 G (±20 mg), 50 G (±30 mg), 100 G (±30 mg), two 200 G (±50 mg), 500 G (±100 mg), and 1000 G (±200 mg). total of 13 masses. This economical set is ideal for general purpose applications. Hinged polypropylene box with snap-tight closure.