I am selling this because I no longer use it. Brand Name: Sony (SONY) Model Number: MDR-CD900ST Series Number: 900 Headphone Jack: 2.5mm jack Communication/Connection Interface: Wired [Pure sound quality that preserves the original sound image] This product thoroughly pursues the quality and durability demanded in the professional world, such as recording studios, post-production, and broadcasting stations, and employs a uniquely developed driver unit. This has successfully achieved clear sound quality with minimal distortion, preserving the original sound image. [Resolution suitable for monitoring] The adoption of a uniquely developed driver unit has also significantly improved the resolution (detection limit) required for monitoring. It meticulously reproduces subtle differences such as the contours of sound, positioning, and the spread of echoes, conveying the "true sound" to the ears. [Suitable for all studio uses] By strengthening the input capacity (maximum input: 1,000mW) and the frame/cover, it emphasizes sound quality while also achieving the durability and stability to withstand use in recording studios and broadcasting stations. By pursuing various conditions from a professional standpoint, it has gained high praise and trust from studio engineers and musicians. [Main Specifications] Extremely high resolution with clear sound contours, and a wide frequency range in terms of hearing, making it easy for musicians to hear the sound. Durability and stability are achieved to withstand use in recording studios and broadcasting stations through strengthened input capacity, frame/cover, elimination of folding mechanisms, and a uniquely developed speaker unit. Type: Sealed, Dynamic Driver Unit: 40mm, Dome type (CCAW adopted) Maximum Input: 1,000mW Impedance: 63Ω Sound Pressure Sensitivity: 106dB/mW Playback Frequency Band: 5~30,000Hz Cord Length: 2.5m Cord Thickness: Φ4.0mm Plug: Stereo standard plug Weight: Approximately 200g (excluding cord) If you have any other questions, please feel free to comment (*ᴗˬᴗ)⁾⁾⁾ Headphones First Take