BenQ treVolo Wireless Bluetooth Portable Electrostatic Speaker -Black Best Sound Experience in Jazz Pop and Classical Music (English Version) Audiophile grade Electrostatic Speaker Technology with unique collapsible wing design for high portability Quad-Amplified electronics with 2.1 channel DSP + precision-tuned duo woofer High standard transmission (CD quality aptX Bluetooth + USB digital line in + Analog line in and line out) 12 hour play time + 3 ambience mode + Noise cancellation high quality speaker phone Free 6 Months Spotify Premium Offer Page (Offer Expires 12/27/15):