{HEAD ~ The reinforcing members} are mechanically clamped between {TAIL ~ inner and outer anchor members} that form the packer heads 
are mechanically clamped between
{ HEAD ~ The reinforcing members } are mechanically clamped between { TAIL ~ inner and outer anchor members } that form the packer heads
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH