Hifiman HE400se Purchased in February 2025. I am selling these as I have acquired a higher-end model. I think they are in relatively good condition, but there is some slight wear on the ear pads. Please check the photos for the condition. The operation is problem-free. HE400se Planar Magnetic Headphones Conventional dynamic headphones have a coil only on a part of the diaphragm, so they cannot directly vibrate most of the diaphragm. Planar magnetic headphones have a coil over the entire surface of the diaphragm. This allows the diaphragm to be driven uniformly by magnetic force, so the distortion of planar magnetic headphones is significantly lower compared to conventional dynamic headphones. Adoption of Acoustically Transparent Stealth Magnets The advanced stealth magnets used in the HE400se are acoustically transparent and are designed to dramatically reduce wave diffraction, which degrades the integrity of sound waves. As a result, distortion is reduced, and a purer sound with beautiful harmonics is obtained. Unlike the sound waves generated by conventional magnets, the specially shaped stealth magnets allow sound waves to pass freely without causing interference. Product Specifications ■ Specifications Frequency Response: 20Hz-20kHz Impedance: 32Ω Sensitivity: 91dB Weight: 385g Included Accessories: High-performance 3.5mm terminal cable, 6.35mm adapter