10 x 4 Oval, 18" Length, 2.25" Bore, Wing 200499

10 x 4 Oval, 18" Length, 2.25" Bore, Wing. A wing configuration refers to a muffler that flows in via an offset, through the length of the muffler, through a mandrel bend at the far end acting as a U-Turn and then out the same end on the other offset, parallel to the inlet.