A cell of the outer peripheral side honeycomb unit in contact with the outermost peripheral cell wall thereof has a corner part having a curved surface, where the corner part is on {HEAD ~ the side} contacting {TAIL ~ the outermost peripheral cell wall} 
contacting
A cell of the outer peripheral side honeycomb unit in contact with the outermost peripheral cell wall thereof has a corner part having a curved surface , where the corner part is on { HEAD ~ the side } contacting { TAIL ~ the outermost peripheral cell wall }
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 OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL