FiiO X5 (2nd Generation) High Resolution Music Player (Gold) High gain reaches 14V (+/-7V), 40% higher than the 1st gen X5, putting the op amps in their best working range, greatly increasing dynamics. Top shelf PCM1792A from Texas Instrument coupled with new OPA1652 gives great dynamic performance Top shelf PCM1792A from Texas Instrument coupled with new OPA1652 gives great dynamic performance BLUETOOTH PLAYBACK: The Boombot PRO pairs with any Bluetooth compatible device including smartphones, MP3 players, tablets and computers. Press the center button for two seconds and ping Siri or Google Voice to ask for directions and much more. RECHARGEABLE LITHIUM ION BATTERY: The rechargeable lithium ion battery lasts through 6 hours of continuous play. When your speaker is out of juice, simply plug it in to recharge using the included 3 foot Micro USB cable. The Boombot PRO also features a 2 Gig flash drive and a 1 year warranty.