I have been a very big fan of buying full ceramic bearings here at VXB. All of the bearings that I have bought up until this product were fantastic. This particular bearing the first angular contact full ceramic bearing that I have bought were absolutely awful. It seems like the tolerances for manufacture are too far off and the bearings don't have any sort of rigidity. I was using a set of this bearing in a bicycle wheel. Both of the bearings pretty much self destructed and crumbled into bits. I would definitely continue buying normal ceramic bearing here at VXB but I don't think I will be trying any more angular contact bearings.