{HEAD ~ The replaceable cutter shell} 49 includes {TAIL ~ a pair} of annular disc elements 50 and 51 
{ HEAD ~ The replaceable cutter shell } 49 includes { TAIL ~ a pair } of annular disc elements 50 and 51
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH