FIIO FT1Pro FIO-FT1PRO-B [Ships from an authorized Japanese retailer, includes serial number] Headphones with open-back, planar magnetic drivers for

FIIO's in-house design features meticulously tuned diaphragms and magnetic circuits. The ideal planar magnetic driver A diaphragm just 1μm thick. A planar magnetic driver that delivers sound quality comparable to that of higher-end models. A two-layer structure that achieves excellent sound quality characteristics. A dual coating of sapphire and aluminum that makes the most of the properties of both. Uniformizes and optimizes the magnetic field. New technology that achieves excellent driving force and suppresses sound distortion. Precise coating at nanometer levels inspired by the semiconductor industry. Delivers outstanding sound quality and excellent durability. Easy-to-use, high-sensitivity design. Low impedance specifications for excellent driving efficiency make it compatible with a wide range of devices. High-frequency response of 7Hz to 40kHz. Powerful performance yet lightweight at 374g and comfortable to wear. Headband designed for comfort. Achieves a comfortable fit with a fine metal adjustment mechanism and suede. Comfortable design that moves in three directions to adapt to the shape of your head. Free angle adjustment for an excellent fit.