{HEAD ~ The blade portion} 12b is shaped like {TAIL ~ a boot}, exposing its rear side 
is shaped like
{ HEAD ~ The blade portion } 12b is shaped like { TAIL ~ a boot } , exposing its rear side
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH