B-Stock, Blue Mo-Fi, headphones with custom high-powered audiophile amplifier, 50mm, fiber-reinforced dynamic driver, sealed over-ear design for superior isolation and feedback prevention, user-adjustable tension and suspension adapt to any head shape, and size for a perfect fit, racecar-inspired multi-jointed headband design keeps earcups parallel, at all times for superior comfort and sound, all-analog amplifier performance modes: passive, active and enhanced bass, powers on and off automatically when headphones are opened and closed, rechargeable battery provides up to 12 hours of playtime; mo-fi continues to play music even when battery has no charge, specifications, amplifier, output power: 240mw, thd+n: 0.004%, frequency response: 15 - 20000 hz, snr, self noise: > 105 db, noise: < 20 uv, battery capacity: 1020mah, impedance: 42 ohms, enclosure details: sealed enclosure with tuned damping materials, package contents : soft case with cable storage pocket, 1.2-meter audio cable with apple iphone/ipad controls, 3-meter audio cable, 1-meter usb charging cable, ac charging adaptor, 3.5mm to 6,3mm trs adaptor, two-prong airplane connector, registration and warranty information, user manual, outer dimensions closed: 210x140x120 mm, outer dimensions open: 180x290x120 mm, weight: 466 g, B-Stock with full warranty, may have slight traces of use