{HEAD ~ The exposed portion} of {TAIL ~ the membrane} 24 is provided with a through hole 30 
of
{ HEAD ~ The exposed portion } of { TAIL ~ the membrane } 24 is provided with a through hole 30
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH