Installing new wheel bearings? If you ride a lot during the year, this is the bearing grade to install for longer life. They cost more, but live a lot longer with initial wp greasing and good seals. Riders getting out a few times a year would be better off with any of the lower grade ball bearings. I'm not knocking the lower grade bearings, but I can only get 700 miles out of them with all the water and mud exposure we have. The lower grade seals sold in the kits allowed water into the hub even with a new spacer kit. Never heard of electric emotor quality as a grade, but the bearing industry does recognize it.