In other embodiments, the joiner may be provided with {HEAD ~ an air outlet portion} such as {TAIL ~ a diffuser outlet} 
such as
In other embodiments , the joiner may be provided with { HEAD ~ an air outlet portion } such as { TAIL ~ a diffuser outlet }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL