The bundle you have chosen is specifically put together for the bicycle application outlined above. In this choice, you have also selected specific bearing technology that correlates to your needs. The precision bearing technology includes; 52100 bearing tool steel balls and races, pre-greased with our standard VG001 bearing grease, one heavy contact (RH) seal and one light contact (RS) seal, a robust PEEK cage, P6 / ABEC 3 precision, and C3 internal clearance. Be sure to click on the bearing part numbers themselves to look at the bearing data more closely.