Optional rear speakers featuring 360 Spatial Sound Mapping for use with BRAVIA THEATER (BAR 8, BAR 9), HT-A7000, HT-A5000, HT-A3000 Soundbars, or STR-AN1000 Receiver. Direct wireless connection with BRAVIA THEATER (BAR 8, BAR 9), HT-A7000, HT-A5000, or HT-A3000 Soundbars, or STR-AN1000 Receiver Built-in battery with up to 10-hour battery life and quick charging Immersive audio from up-firing speakers Activate Sound Field Optimization with OPTIMIZE button Flexible layout – no power outlet needed Omnidirectional Block Design with room-filling sound Wall mount-capable rear speakers Note: Product volume maximum is reduced when running on battery and depends on battery charge level. Volume level is also dependent on the source content. Rear satellite speakers do not power on automatically when in battery mode; they require the Power Button to be pressed to turn on. Auto On feature works when the device is plugged into power. Please refer to the user manual provided in the product catalog for additional information.