The retainer is inserted into {HEAD ~ the retainer insertion hole} and held in {TAIL ~ a temporarily secured position} 
The retainer is inserted into { HEAD ~ the retainer insertion hole } and held in { TAIL ~ a temporarily secured position }
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL