Each pocket is formed into {HEAD ~ a shape} forming a narrow opening portion at the inner race side and {TAIL ~ a wide opening portion} at the outer race side 
Each pocket is formed into { HEAD ~ a shape } forming a narrow opening portion at the inner race side and { TAIL ~ a wide opening portion } at the outer race side
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH