Converts for Black and Decker 40V lithium batteries to for Milwaukee 18V lithium battery, enabling the use of various high-capacity batteries with Milwaukee tools. Compatible with multiple Black and Decker 40V lithium battery models, including BL4040, BL4025, BL4045, and BL4045F, ensuring versatility in tool usage. Built-in voltage protection chip enhances safety and reliability, while the high-quality ABS plastic construction ensures durability. Easy to install and remove, this adapter fits well with 18V tools, providing a hassle-free experience compared to original adapters. Note that this is an adapter, not a battery; it cannot be used for charging power tool batteries and should be removed before charging. The BD40MIL18 battery adapter is designed to maximize the efficiency of your cordless power tools by allowing the use of Black and Decker 40V lithium batteries with Milwaukee 18V tools. This innovative adapter is perfect for those who want to extend the life and performance of their tools without the need for multiple battery types. With its robust construction and safety features, you can work confidently both indoors and outdoors. Color: Black Material: ABS Package Contents: 1* Battery Adapter