Set of weights used to calibrate accurate scales and balances.
Scales are measured at specific intervals and these weights allow a complete set of test numbers to provide a complete data set to determiner if a scale measuring is within the required range at many different weights.
We have many scales from larger stand on scales up to 600 lbs, to counter top digital scales to an analytic balance for our lab set that is accurate to +- 0.0001 grams.