Adapter DM18RL MT20RNL BPS18RL use For RYOBI/Makita/Dewalt/Milwaukee Black Decker Porter-Cable Stanley Li-ion Battery 18V Tool - AliExpress
Amazon.com: 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 :
Home Depot takes up to $200 off Milwaukee, DEWALT, more + $199 6-tool RYOBI combo kit
Milwaukee and Ryobi Angled Drill Adapters – WoodBin