{HEAD ~ an outer sealing member} extending from {TAIL ~ ends} of the towers and which covers the two openings, and 
{ HEAD ~ an outer sealing member } extending from { TAIL ~ ends } of the towers and which covers the two openings , and
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH