The hollow cage has {HEAD ~ rows} of {TAIL ~ cross sectional holes} that communicate with the ports 
of
The hollow cage has { HEAD ~ rows } of { TAIL ~ cross sectional holes } that communicate with the ports
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH