Milwaukee 18V to CAT 18V Battery AdapterThe Milwaukee M18 to CAT 18V Battery Adapter allows you to use your Milwaukee M18 18V batteries with compatible CAT 18V Caterpillar cordless tools, giving you more flexibility from the battery platform you already own. Instead of purchasing additional CAT 18V batteries, this adapter lets you power your CAT 18V tools using Milwaukee M18 batteries through a simple plug and play connection. Whether you are working on home projects, repairs, or jobsite