Motor Grounding Ring Compatible Motor Frame 250M (4 6 or 8-Pole) 280M 280S 315M 315S 351L (2-Pole) For Motor Frame Type IEC For Nominal Shaft Diameter 65 mm Material Aluminum Ring Construction One Piece Ring Outside Diameter 99 57/64 mm System of Measurement Metric Features Designed to Help Extend Motor Life by Safely Diverting Harmful VFD