This idler pulley with OE/OEM part number 4991240 is a perfect fit for DCEC Cummins Engine ISDe and ISBe. It is manufactured in China by a well-known brand and is designed to provide optimal performance. The pulley is made of high-quality materials that ensure durability and longevity. The idler pulley is an essential component of any engine and plays a crucial role in the smooth operation of the vehicle. It helps in maintaining the correct tension of the accessory belt, which is critical for the proper functioning of other components. With this idler pulley, you can be assured of a reliable and efficient engine system.