The FLY 103 ACOUSTIC is the official extension speaker for the FLY 3 ACOUSTIC compact mini amp. The FLY 103 ACOUSTIC comes with its own built-in cable to connect it to the FLY 3 ACOUSTIC, making it a true stereo set-up. The extension cabinet is sold separately or as part of a FLY ACOUSTIC Stereo Pack that provides a power supply to power both units. When connected to the FLY 3 ACOUSTIC is makes a set of portable speakers to play your music through or it can be used as a set of pc speakers or computer speakers.