{TAIL ~ The exterior surface} of the ferrule comprises {HEAD ~ a circumferential ridge} and groove that reversibly interacts with a spring inside the adapter cavity 
{ TAIL ~ The exterior surface } of the ferrule comprises { HEAD ~ a circumferential ridge } and groove that reversibly interacts with a spring inside the adapter cavity
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH