The headrest 3 illustrated is made of {HEAD ~ a metal plate channel} shaped in section taken along {TAIL ~ the line III III} in FIG 2 
The headrest 3 illustrated is made of { HEAD ~ a metal plate channel } shaped in section taken along { TAIL ~ the line III III } in FIG 2
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH