Function and benefit: Enables using 20V Max Lithium batteries in most 18V XRP NiCad NiMh tools, extending runtime without upgrading your entire toolkit. Works with 20V batteries in the Dewalt system to power 18V tools. Compatibility: Compatible with Dewalt 20V Max Lithium batteries DCB200, DCB201, DCB203, DCB204, and DCB206, for use in Dewalt 18V XRP NiCad NiMh tools (DC9096 family). Easy installation and removal: Designed for quick and secure installation in Dewalt 18V tools, with a fit that is straightforward to remove when needed and more convenient than some original adapters. Important notice: This is a replacement for the standard 20V battery adapter and does not require charging on its own. Please remove the adapter before charging the 20V battery. Clear use scenarios: On a job site, run an 18V drill longer by using a 20V Max battery to reduce frequent battery swaps. In a workshop with multiple 18V tools (drill, impact driver, reciprocating saw), share a single 20V battery across tools using the adapter. While upgrading your toolkit, continue using existing 20V Max cells in 18V XRP NiCad/NiMh tools for cost efficiency and flexibility.