This fan spacer is a must-have for anyone running a Cummins Diesel Engine M11 QSM ISM. It is designed to perfectly fit and enhance the performance of your engine. The spacer is manufactured in China and comes as a single unit. With this fan spacer, you can expect improved engine cooling and increased efficiency. It is a high-quality product that is built to last. Make sure to add this to your list of essential engine components.