Converts for 40V lithium batteries to for 18V lithium battery, enabling the use of high-capacity batteries with tools. Compatible with multiple 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 40V lithium batteries with 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 Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.