Economical weights are economical, quality weights. Individual weights are available from 1 mg through 2000 G. Weights are adjusted to tolerances specified by ANSI/ASTM E617 Class 7. Economical Class 7 weights are manufactured from stainless steel and are cylindrical in shape for easy gripping. Weights 1 G to 100 G are of one-piece construction and are adjusted during manufacture by removing material from the bottom of the weight. Weights 200 G through 2 kg have an adjusting cavity on the top that is sealed with a plug. Economical stainless steel weights 1 G and above are perfectly flat on top to stack easily on center. Weights 500 mg and lower are made of stainless steel or aluminum and are flat, one-piece construction with one side turned up to make them easy to handle with Forceps. 500 mg and 200 mg weights are made of stainless steel while weights 100 mg and below are made of aluminum. Suggested markets for economical stainless steel weights include, but are not limited to, educational markets what's included: weights are supplied by the vendor with a traceable calibration certificate or a Statement of accuracy ASTM Class 7 - for rough basic weighing operations two-piece weights with adjusting cavities.