{TAIL ~ The lower discharge surface} is spaced apart from {HEAD ~ the upper discharge surface} by a distance equal to D1 
{ TAIL ~ The lower discharge surface } is spaced apart from { HEAD ~ the upper discharge surface } by a distance equal to D1
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH