The SA-RS5 speakers work with Sony's latest compatible soundbars using up-firing speakers and wide directivity woofers for 360 Spatial Sound Mapping to create multiple phantom speakers around your room. When you’re surrounded on all sides by multiple phantom speakers within an optimized sound field, you’ll hear every sound with incredible intensity. It’s like you and your living room are inside the movie. With up to 10 hours of battery life when fully charged you can set these speakers without worrying about an AC cable. You can charge them out of sight and bring them out when you need them. And if you’re in a hurry, just 10 minutes of charge will give 90 minutes of use. Activate Sound Field Optimization any time by pressing the OPTIMIZE button on the unit. These speakers combined with a compatible soundbar intelligently measure the distance between speakers and ceiling using dual microphones in each speaker for smart and easy set up. FEATURES Optional rear speakers featuring 360 Spatial Sound Mapping for use with HT-A7000/ HT-A5000/ HT-A3000 Soundbar Direct wireless connection with HT-A7000/ HT-A5000/ HT-A3000 Soundbar Built-in battery with up to 10-hour battery life and quick charging Activate Sound Field Optimization with OPTIMIZE button Total 180W power output brings music and movies to life Flexible layout – no power outlet needed Omnidirectional Block Design with room-filling sound TECHNICAL SPECS Battery Life: 10h Built-in battery: Yes PLAY TIME IN 10MIN QUICK CHARGE: 90min Charge Time: 4h Amplifier Type: Digital Amplifier, S-Master Amplifier Channels: 6ch(L:3ch+R:3ch) Power Output (Total): 180W(L:90W+R:90W) Rear speaker size (W X H X D) (MM): 145x250x134mm, 5 3/4 in x 9 7/8 in x 5 3/8 in REAR SPEAKER WEIGHT (KG): 2.4kg, 5lb 5oz