{TAIL ~ The opening} 52 is delimited by {HEAD ~ a cylindrical drip ring} or flange 54 
{ TAIL ~ The opening } 52 is delimited by { HEAD ~ a cylindrical drip ring } or flange 54
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH