said {HEAD ~ mounting fixtures} being capable of inverting {TAIL ~ a mounting direction} of said device relative to a second user; and 
capable of inverting
said { HEAD ~ mounting fixtures } being capable of inverting { TAIL ~ a mounting direction } of said device relative to a second user ; and
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH