A retainer 1 wherein said entering nose portion has {HEAD ~ a rounded exterior surface} and {TAIL ~ an inner enlargement} 
A retainer 1 wherein said entering nose portion has { HEAD ~ a rounded exterior surface } and { TAIL ~ an inner enlargement }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL