{HEAD ~ Notches} 324 are formed along {TAIL ~ the outer peripheral edge} of the base portion 318 
are formed along
{ HEAD ~ Notches } 324 are formed along { TAIL ~ the outer peripheral edge } of the base portion 318
HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH