Amazon.com : DM18M Battery Adapter for Dewalt 20V Convert to for Makita 18V Lithium BL1830 BL1840 BL1850 14.4V-18V Battery : Tools & Home Improvement
Torubia Battery Adapter for Milwaukee to Makita Battery, for Milwaukee 18V for Dewalt 20V Battery Convert to for Makita 18V Battery(Black) - Walmart.com
Aku Adapter DeWALT / MAKITA - AkuAdapter
FirstPower Battery Adapter for Makita 18V Lithium-ion Power Tools,Convert Milwaukee 18V or Dewalt 20V Lithium-ion Battery to Makita 18V Lithium-ion Battery - - Amazon.com