{HEAD ~ The insert} has {TAIL ~ two arms} that each extend from the intersection of imaginary extensions of the secondary locating sides 
has
{ HEAD ~ The insert } has { TAIL ~ two arms } that each extend from the intersection of imaginary extensions of the secondary locating sides
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH