Perfectly Tuned You get more boom with Sony's proprietary DSEETM (Digital Sound Enhancement Engine) and Clear Audio+ TM technology which together improve the bass, clarity and restore audio quality to deliver rich and refined sound -Let's get Music Started. Stay Connected Wirelessly No cords, no tangles, no holding back. With NFC, one tap is all it takes to switch it on, activate Bluetooth, pair with your phone and start playing! Charge up SRS-X55 features 2200mAh battery that gives you 10 hrs. playback and also help you to charge portable devices while you're on the move enjoying & partying . Built-in Microphone Simply press the built-in speakerphone button and take calls hands-free, without losing track of your playlist!