The HMDX Grey JAM Plus Wireless Speaker improves over the original by allowing you to pair a 2nd Jam Plus speaker for true stereo sound. With its rechargeable lithium ion battery, The JAM Plus supplies up to four hours of playing time at a range up to 30 feet through built in Bluetooth. For devices that don’t have Bluetooth, use the provided line-in connection. Available in multiple colors. (NOTE: you can NOT pair the JAM Plus with a JAM Classic).