The system 15, wherein a midsection of each of the longitudinal sidewalls extends towards {HEAD ~ a central region} of {TAIL ~ the body} 
The system 15 , wherein a midsection of each of the longitudinal sidewalls extends towards { HEAD ~ a central region } of { TAIL ~ the body }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL