{TAIL ~ The width} of the valve member is smaller than {HEAD ~ a peripheral dimension} of the openings 
{ TAIL ~ The width } of the valve member is smaller than { HEAD ~ a peripheral dimension } of the openings
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH