The center portion 46 has a width such as to only block a portion of the inner passageway 44D such that air is able to pass around {HEAD ~ the center portion} 46 between {TAIL ~ the ends} 44A and 44B of the body 44 
The center portion 46 has a width such as to only block a portion of the inner passageway 44D such that air is able to pass around { HEAD ~ the center portion } 46 between { TAIL ~ the ends } 44A and 44B of the body 44
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 REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH