iSound Twist Rechargeable Bluetooth Speaker & Speakerphone - Green A2DP Bluetooth with a 30 foot transmission range for wireless music streaming Built-in microphone with advanced noise cancellation for crystal clear speakerphone calls Rechargeable Lithium-ion battery offers 5 hours of continuous playtime Features two speakers and one passive radiator sub-woofer Also works with any device that has a 3.5mm audio plug such as MP3 players, iPods, iPads, iPhones, Android Phones, Blackberry, and Tablets (including the Kindle Fire)