It consists of {HEAD ~ an array} of {TAIL ~ plates}, serrated on an edge, and assembled in a block whose midline is continuous with the entry to the fixed guide 
of
It consists of { HEAD ~ an array } of { TAIL ~ plates } , serrated on an edge , and assembled in a block whose midline is continuous with the entry to the fixed guide
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH