F2 class weights
These weights are of high metrological accuracy and are used as reference standards for calibrating other lower class weights like F1 and below classes, F2 class weights are integral(1mg to 10 g) /two-piece (20 g to 50 kg) type weights, These weights have adjustment cavities for adjusting the weights(20 g to 50 kg). These weights are appropriate for the calibration of medium-precision analytical balances
