... iron core, no hysteresis and cogging, low starting torque.2.No mechanical friction, above 98% of generation efficiency. ... with unique coreless technical design4.Large output, with rare earth permanent magnet, multi-polar, small gap, high power density5. ... With brushless structure, free of maintenance, More than 20 years of working life.Product specifications: ItemSpecificationunitValue1Rated PowerKW0. ...