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