Premium solid black walnut is carefully milled into a headphone housing, showcasing a design that beautifully echoes the artistry of traditional Japanese woodworking. These headphones are assembled one by one in limited quantities at a Japanese factory, marking a special commemoration of Fostex's 50th anniversary. Open-back housing to evoke the imagery of sunlight filtering through the trees. Elegantly crafted with a touch of Japanese aesthetics. Carved from black walnut, a globally renowned wood. Combines excellent structural rigidity with exceptional acoustic qualities. The design draws inspiration from the captivating natural phenomenon where sunlight produces a radiant glow as it filters through the spaces amidst trees. This precision-machined design not only upholds structural rigidity but also effectively eliminates the generation of modal vibrations. Each opening is meticulously sized to prevent resonance at particular frequencies. Leveraging years of accumulated expertise, bio-cellulose fibers are skillfully blended with other materials under optimal conditions. This results in achieving a low specific gravity, high Young's modulus, and high internal loss. These properties enable the faithful reproduction of delicate, high-resolution, and beautiful mid-high frequencies. The inclusion of a free edge enables the accurate reproduction of low mid-range frequencies with substantial amplitude. *BIODYNA is registered trademark owned by Foster Electric Co., Ltd. Exceptionally robust magnetic circuit. The magnetic circuit boasts a 50mm driver unit with an impressive magnetic flux density of 1 Tesla. This ultra-strong magnetic circuit ensures minimal distortion and a wide dynamic range. High quality and lightweight mechanical parts. Aluminum is widely employed for mechanical components to attain a superior quality feel while keeping the product lightweight. Incorporating high-specific-gravity resin for the baffle plate effectively