The upper end is optionally secured to {HEAD ~ the open lower end} of {TAIL ~ the T} shaped two piece housing 
of
The upper end is optionally secured to { HEAD ~ the open lower end } of { TAIL ~ the T } shaped two piece housing
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH