{HEAD ~ The outer peripheral side honeycomb unit} has an outer peripheral cell wall forming {TAIL ~ the outer peripheral surface} of the outer peripheral side honeycomb unit 
{ HEAD ~ The outer peripheral side honeycomb unit } has an outer peripheral cell wall forming { TAIL ~ the outer peripheral surface } of the outer peripheral side honeycomb unit
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH