first retaining means comprising a plurality of {TAIL ~ radially extending means} on {HEAD ~ said retaining ring}, 
first retaining means comprising a plurality of { TAIL ~ radially extending means } on { HEAD ~ said retaining ring } ,
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH