Twelve South BassJump 2 for MacBook | Portable add-on subwoofer for MacBook USB powered subwoofer designed exclusively for MacBook and MacBook Pro Dramatically improves the sound performance of your MacBook speakers One USB connection provides both power and digital audio to BassJump Compatible with - MacBook Pro (13, 15 or 17-inch) ; MacBook (black, white or aluminum); MacBook Pro with Retina ; MacBook Air and iMac & Cinema Display