FiiO FT1 Closed-Back Over-Ear Nanowood Fiber Composite Diaphragm Wired Hi-Fi Headphones, Detachable Cable, American Black Walnut Wood Ear Cups for Home, Studio, Recording (Beech Wood) Nano wood fiber composite diaphragm: The diaphragm of the FIIO FT1 earphones is primarily made from selected wood fibers, with a base material of 90-year-old spruce from Northern Europe. It incorporates a specific proportion of carbon fiber material, resulting in a diaphragm thickness of approximately 0.1mm. This design achieves a balance of lightweight and durable physical properties. W-shaped independent suspension design: Derived from FIIO's latest self-developed acoustic technology, the W-shaped independent suspension design increases the effective vibrating area of the diaphragm by 25.8% compared to conventional diaphragm designs of the same size. This larger effective diaphragm area and amplitude allow the acoustic core unit to store more sound energy. North American black walnut solid wood ear cups: The FT1 earphones feature premium North American FAS grade black walnut solid wood ear cups, known for their exquisite texture that offers an immersive experience of natural beauty from the original wood material. The high-density solid wood not only effectively reduces cavity resonance and minimizes standing waves but also ensures that each piece of wooden ear cup has a unique grain pattern, making it distinctly yours. Portable lightweight headband: The FT1 features a steel ball slide rail headband design, significantly enhancing its durability. Compared to other products in its class, the FT1 offers an extensive adjustment range from 0 to 11 notches to accommodate various head sizes. The headband contact area is covered with suede fabric, ensuring a comfortable and breathable experience, making it both refreshing and durable. Standard with two oxygen-free copper silver-plated headphone cables: The audio connectors include a 3.5mm single-ended and a 4.4mm balanced plug. Both cables feature identical specifications, utilizing oxygen-free copper with silver plating and containing 392 strands of wire. Each cable measures 1.5 meters in length and has a diameter of 24AWG