The 3975818 Original Oil Cooler / Core Cooler is specifically designed for Cummins ISBe / QSB 6.7L diesel engines. Made by the trusted brand Cummins, this oil cooler is compatible with equipment that utilizes a 6 cylinder, 12 valve engine like the 6BT 5.9L model. This unit quantity of 1 is essential for maintaining optimal engine performance and keeping the engine’s temperature regulated. Ideal for heavy equipment and industrial applications, this oil cooler is a reliable and efficient component for diesel engine cooling needs.