{HEAD ~ The exit cover} is disposed over {TAIL ~ the exit trough} and the lateral trough section 
is disposed over
{ HEAD ~ The exit cover } is disposed over { TAIL ~ the exit trough } and the lateral trough section
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH