The PRS angular contact ball bearing including three series : accurate angular contact ball bearing ,double direction angular contact thrust ball bearing ,four-point angular contact ball bearing .It has many advantages ,for example : high precision ,good rigidity ,low tempering ,high rotating speed ,low friction, long life ,strong instantaneous change between low and high speed, and convenient mounting and dismantling .It can be widely applied to the prime axis of precise machine tools with high speed and other prime axis of precise machinery with high speed.