Notebook/Laptop Computer Accessories -- Premier Mobile Theater Speakers. Features - 1.Dual speaker cones deliver crisp, clear sound. 2.Digital audio signal with 3D 7.1 virtual surround sound produces superior small speaker performance. 3.Self-powered USB 2.0 interface eliminates the need for an external power supply. 4.Lightweight, compact design and included carrying bag provide maximum portability while traveling. 5.Included stands provide maximum placement for the highest quality surround sound.