Compatible with: DeWALT 20v Max including 20-60v Flexvolt Batteries. Simply connect your battery to experience superior stereo sound! Our primary focus is on low-voltage protection. To prevent overload damage, the speaker will automatically power off if the battery voltage drops below 15.5v. Versatility: Speaker is functional with Bluetooth and USB Audio Disk. Bluetooth 5.3 ensures rapid & stable pairing with your devices. Strong connection is guaranteed up to 52 ft. For USB music playing, simply plug-in the USB disk into the USB port to enjoy the pure crispy sound!