BlueAnt X2i delivers deep rich lows and crystal-clear highs for a stellar sound that sparkles. BlueAnt's Signature Studio Engineered Audio breathes new life into your music with an enhanced dynamic range and improved performance to life your audio to new heights. Patented Shimmer weave fabric that looks as good as it sounds. Built in rechargeable battery provides up to 12 hours of playtime*. Simply Pair two X2i's, or an X2i and an X1i, to double the fun and deliver a wide stereo soundstage.