Denon HEOS 1 GO Pack

Lithium-ion rechargeable battery with battery strength indicator LEDs;
Up to 6 hours of playback on a single charge via Bluetooth, Wi-Fi or Aux In;Bluetooth USB adapter included for wireless audio streaming away from the network
Easy twist-on/twist-off attachment to the HEOS 1 base; Charge your smartphone while listening to music at the same time