Providing the perfect balance of great sound, iconic design, and premium materials, the Onyx Studio 4 is the epitome of room-filling audio. Crafted to be the best sounding, full featured, portable Bluetooth speaker in its class, Onyx Studio 4 offers two device connections to alternately play audios from both. Its powerful 3000mAh battery delivers up to 8 hours of playtime, and the built-in microphone is made for crystal-clear conferencing over the speaker. Amplify your listening experience with HK Connect+, which accommodates 100+ Harman Kardon speakers in one network. Besides, it can be easily controlled with your voice.