Amazon.com: Echoyee for Dewalt & for Milwaukee to Ryobi Battery Adapter, Fit for Dewalt 18v-20v & for Milwaukee 18v M18 Lithium Batteries, DM18RL Converter use for Ryobi 18v ONE+ Cordless Power Tools :
For Ryobi One+ 18v Tool Adapter Convert For Dewalt For Milwuakee 18,for Black Decker Porter Cable,stanley 18/20v Battery - Power Tool Accessories - AliExpress