In the 45BLW motors (16 poles design), the permanent magnets are on the external rotor which rotate around the internal stator with the windings. Delta Line says that, in addition to the shorter design, the advantage of this construction compared to internal rotor motors comes from having the same output with lower torque ripple due to the rotor’s higher moment of inertia. 

The motors can be produced according to customer-specific requirements for voltages from 12-48V and a power of 25-80W – with and without hall sensors. Southern Manufacturing Stand P49