I purchased these from Soundhouse several years ago and used them as DTM monitor headphones. The current retail price is 19,800 yen. 【Please Note】 ・Only the left side produces sound; the right side does not. I hope someone who can use them for parts or repair them themselves will take them as junk. ・The ear pads have been replaced with CLASSIC PRO ones, but they are torn and deteriorated with age. (They can still be used, but the black fabric will fall off.) ・There is no outer box. They will be wrapped in cushioning material and shipped in a cardboard box. 【Product Information】 MDR-CD900ST Brand: SONY Structure: Closed-back Wearing style: Both ears, integrated left and right Earphone/Headphone type: Headband type Color: Black Low-frequency response (Hz): 5.0 Hz High-frequency response (kHz): 30.0 kHz Wireless/Wired connection: Wired connection Driver type: Dynamic Plug shape: Standard plug Impedance (Ω): 63.0 Ω Sound pressure sensitivity (dB): 106.0 dB Driver size (mm): 40.0 mm Cord length (m): 2.5 m Weight (g): 200.0 g ※Instant purchase welcome, no smokers or pets ※Please feel free to comment with any questions or requests for additional images before purchasing. ※We use recycled materials for cushioning and cardboard for shipping. ※We are sorry, but we cannot accommodate exclusive offers to avoid any trouble. Thank you very much.