Equip your semi truck to be ready for the journey ahead with seamless exhaust connections, with the OTR 5" to 4" Aluminized Exhaust Reducer with Expertise Built In™. Due to its sophisticated design, this replacement device is able to reduce the diameter of an exhaust pipe so that it can tightly seal with smaller-sized components. Crafted with an aluminized pipe for added corrosion resistance. FleetPride is your First Click in Heavy Duty®.