The cell densities of the flow through honeycomb substrate 200 and the wall flow particulate filter 300 may or may not be the same, where cell density is {HEAD ~ the number} of {TAIL ~ channels} per cross sectional area of the honeycomb substrate 
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The cell densities of the flow through honeycomb substrate 200 and the wall flow particulate filter 300 may or may not be the same , where cell density is { HEAD ~ the number } of { TAIL ~ channels } per cross sectional area of the honeycomb substrate
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 HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH