{HEAD ~ A retainer ring} can be installed at {TAIL ~ the end} of the tubular body opposite to the flange to secure the surgical port in the body wall 
installed at
{ HEAD ~ A retainer ring } can be installed at { TAIL ~ the end } of the tubular body opposite to the flange to secure the surgical port in the body wall
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH