Mocole X05 Wireless Bluetooth 1800mAh Li-Ion Rechargeable Speaker with Built-in Speakerphone (Black - Aluminum Alloy Casing) New upgraded Bluetooth CSR4.0 version (vs CSR2.0) with even better sounding specifications True 3W+3W output for high quality stereo sound with noise reduction for answering phone calls from your smart phone. Rechargeable 1800mAh lithium-ion battery can play up to 8 hr of music playback and quickly recharges in 3hrs. Speakers are made of woven Kevlar diaphragm with spider and neodymium magnets, providing bass to as low as 40hz Housing is constructed of real aluminum with leather-like handle and brushed aluminum buttons