DBEST London PS4007BT-RB Transformative Bluetooth and MP3 Hi-Fi System - Retail Packaging - Black Convertible futuristic design that lets you transform the system into dozens of different shapes to complement your mood and environment Two powerful amplifiers for surprisingly loud and clear sound for both wireless and wired music playback Integrated microphone for hands-free conference calling & OLED display provides caller ID, track information and more Standalone MP3/WMA microSD player Built-in 1700mAH Lithium Polymer Battery facilitates up to 50 hours of playback time