The model of the blade corresponds to the size of the U-drill
SPMG050204-------- U-drill 13-15
SPMG060204-------- U drill 15.5-21.5
SPMG07T308-------- U drill 22-27.5
SPMG090408-------- U drill 28-33.5
SPMG110408-- ------U-drill 34-41
SPMG140512-------- U drill 42-50
SPMG090408-------- U drill 51-60
Attention: If the manufacturers of U-drills are different, there may be some errors in the size of the inserts used.