Same like in kit, for spare purposes, thogh, my HK-600 has now abount 100 flights without any issue. But, you never know, so better to have it in stock at home.They are for blade grip ! Egal quality from original HK kit. No problem with. I purchase the other bearings for my 600GT, and all the same quality and brand.
All my bearing from original kit have most of 70 flights, and no problem. Must be oiled time of time !