2-1 Device powers an OZRadial 400B as well as any smart device that chares with a USB cable. Have a power bank ready for your ozone generators.* Compatable with the OZ Radial 400B & Radial EZ* An added 6 extra hours of battery lifeTo destroy more odors longer * Includes a 21V DC power supply For convenience * OZ products are not intended for in-the-field use.WARNING: Ozone products are intended for use in unoccupied spaces