Description Freightliner Exhaust Tube Repalces OEM: A04-21270-000. This exhaust tube is manufactured in the USA from high-quality 304 Stainless Steel. Tube inlet size: 5″ Flare Tube outlet size: 5″ Hose beaded: No Fitting sizes: ¼ NPT Base tube dia. 5″ Material: 304 stainless steel