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