At {HEAD ~ the opposied corners} of {TAIL ~ the trapezoidally shaped crotch portion} adjacent the side of the crotch portion which is spaced from, and extends parallel to, the longitudinal axis of the elongated wing portions, the crotch portion carries a pair of securing elements 
of
At { HEAD ~ the opposied corners } of { TAIL ~ the trapezoidally shaped crotch portion } adjacent the side of the crotch portion which is spaced from , and extends parallel to , the longitudinal axis of the elongated wing portions , the crotch portion carries a pair of securing elements
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH