The OTR 4" x 12.6" Exhaust Pipe Bellows are the ideal replacement to prevent exhaust leaks and loss of engine power. Made of durable steel, this bellows is designed for increased durability and longer service life. It includes all the hardware required for complete replacement and is easy to install, fitting most PACCAR engines. With this bellows, you can be sure that your engine will be running at its best. FleetPride is your First Click in Heavy Duty®.