Ufo, the flagship Bluedio U(UFO) by Bluedio, is first and foremost committed to one thing: the superb sound, achieved by New technical innovations: Bluedio exclusive pps 8 technology, built-in 3D DSP processor and 24-bit high-speed signal processing. Furthermore, ufo is beautifully crafted with the top-notch aviation material: al-it alloy, sturdy enough to be unbreakable and durable with extreme lightweight. And its incredible power is enhanced by the latest Bluetooth 4.1 chip: continuous music playing time is up to 25 hours. Altogether, ufo redefines what reference-level wireless audio is all about. Bluetooth version: Bluetooth 4.1 supported profiles: A2DP, AVRCP, HSP, HFP drivers: φ50mm x 2 ；φ20mm x 6 impedance: 32ω SPL: 120 db THD: 0.3%-3% frequency response: 5Hz -25000Hz wireless range: 30 ft. (Free space) music time: about 25 hours talk time: about 28 hours standby time: about 1300 hours( 50 days) charging time: 3 hours for full charge headphones dimensions: 8.1”X 7.1”X 2.76” package dimensions: 9.4”X 9.1”X 4.7” headphones weight: 11.89 oz. Package weight: 47.6 oz. In the box: Bluedio ufo Bluetooth headphones audio cable USB charging cable manual carrying case with a Buckle.