The base member, post, and {HEAD ~ closure member} may be composed of {TAIL ~ a wide variety} of materials 
The base member , post , and { HEAD ~ closure member } may be composed of { TAIL ~ a wide variety } of materials
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH