GRAM M1 Stainless Rectangular weights are machined in stainless steel with a rectangular profile, covering a range from 5 kg to 20 kg for the calibration and verification of balances. They deliver dependable OIML M1 class accuracy, with a maximum permissible error of just ±50 mg at a nominal value of 1 kg — the right choice for traceability of M2 and lower-class weights, and for verifying weighing instruments of OIML accuracy class II. The rectangular shape provides a stable footprint for handling heavier reference masses, while the stainless-steel body withstands daily use in industrial, laboratory and calibration environments. Optional M Class traceability certificates for 5, 10 and 20 kg add documented proof of accuracy.