Weights are made of brass, with nickel plated surfaces. All weights are carefully tested and calibrated (but not certified).Analytical Weight Box contains 9 weights (1 each of 1g, 5g, 10g, 50g and 100g sizes, and 2 each 2g and 20g sizes), in polished wooden box, with a 1 to 500 mg fractional weight set, 5mg rider and forceps