This creates a generally flat surface on {HEAD ~ the top} of {TAIL ~ the dome} with the dome like sides sloping away from, and generally not engaging, the diaphragm 
of
This creates a generally flat surface on { HEAD ~ the top } of { TAIL ~ the dome } with the dome like sides sloping away from , and generally not engaging , the diaphragm
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH