a box like {TAIL ~ housing} having a first inlet for exhaust gas formed in a first wall thereof, a first outlet for the exhaust gas formed in a second wall thereof and a second outlet for the exhaust gas formed in {HEAD ~ a third wall} thereof, said second and third walls being arranged at right angles with each other 
a box like { TAIL ~ housing } having a first inlet for exhaust gas formed in a first wall thereof , a first outlet for the exhaust gas formed in a second wall thereof and a second outlet for the exhaust gas formed in { HEAD ~ a third wall } thereof , said second and third walls being arranged at right angles with each other
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL 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 OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH