{HEAD ~ The particulate matter reducing apparatus} 1, wherein each of the filters has a central through hole of a diameter approximately the same as or greater than that of the exhaust pipe and smaller than {TAIL ~ half the outer diameter} of the filter 
{ HEAD ~ The particulate matter reducing apparatus } 1 , wherein each of the filters has a central through hole of a diameter approximately the same as or greater than that of the exhaust pipe and smaller than { TAIL ~ half the outer diameter } of the filter
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH