a ring with a flattened shape fastened to {HEAD ~ the upper end} of {TAIL ~ the enclosure}, and 
of
a ring with a flattened shape fastened to { HEAD ~ the upper end } of { TAIL ~ the enclosure } , and
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH