Bluetooth 4.1 lets you wirelessly connect to your smartphone, tablet, and other Bluetooth-enabled music devices to keep you entertained wherever you go Crafted with REWIND fabric cover using a combination of hemp, organic cotton, and recycled plastic bottles, as well as stained bamboo detailing on the front and rear panels 1-inch dedicated tweeters and 3.5-inch high-output woofers deliver impressive audio quality with great highs and lows for a very enjoyable listening experience Built-in speakerphone lets you answer calls without having to fumble for your phone Reliable rechargeable lithium-ion battery lasts up to 8 hours on a single charge Auxiliary input lets you manually connect iPods, MP3 players, and other music devices without Bluetooth