... impedance matching - Powered by 12.6V Li-polymer battery pack, or external 16V power adapter- 40 hours play time with stock opamps ... Class A*2, BUF634U*2, dummy adapter*2)- High output power, 600mW+600mW into 32Ω- High quality components, such as, gold ... jacks. - Measures 55*24*92mm, and weighs 156g- Comes with power adapter, leather pouch, rubber feet, connection cable, warranty card, and ...