The middle member may comprises a composite of alternating layers of {HEAD ~ wire trusses} and {TAIL ~ polystyrene foam} 
The middle member may comprises a composite of alternating layers of { HEAD ~ wire trusses } and { TAIL ~ polystyrene foam }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL