The BESTfit Tube and Fin Charge Air Cooler 35 x 25.25 Inch from 4 State Trucks is an aftermarket cooler designed as a direct replacement for units in Kenworth W900B and W900L trucks from 2007 through 2009, including AeroCab variants. It is engineered to meet original equipment specifications with a heavy-duty tube and fin core that measures 35 inches tall, 25.25 inches wide and 2.75 inches thick, and it uses 4-inch inlet and outlet connections that align with common factory piping to help maintain efficient charge air cooling. This cooler is tested to be 100 % leak-free and is offered both sold individually or as a complete kit, with the kit including four heavy-duty clamps, two red 4-inch silicone hoses and a set of mount bushings to assist installation. It is designed to replace OEM part numbers F31-1068 and F31-1047 when proper OE references, dimensions and hose connection sizes are verified before purchase. Both the standalone cooler and the kit option are backed by a warranty against defects in workmanship and materials from the date of purchase. Because this item is an aftermarket part rather than an original equipment component, verifying fitment for your specific W900 model year and configuration before ordering is recommended.