The input flanges of the gearbox must match the flange of your motor B5 (plain hole flanges) or B14 (threaded hole flanges). - For mounting an IEC motor with frame size 63 to 112 - For B5 or B14 motor flange. For direct coupling with an electric motor, the flange is located on the gearbox input. In this case, the flanges are PAM flanges (Motor coupling prearrangement). The PAM flanges are available in B5 or B14 version (smaller and more compact than the B5).