K224 Brand new, unused. Sennheiser HD 599 SE Wired Headphones, Open-Back, Black Brand: Sennheiser Color: Black Wearing Style: Over-Ear Headphone Type: Open-Back Impedance: 50 ohms Noise Control: None Type: Dynamic, Open-Back Amazon-exclusive model of the HD599, a high-end model in the HD500 series, featuring Ergonomic Acoustic Refinement (E.A.R.) technology. Amazon model exclusive packaging. Large, high-quality ear pads are thick and provide a light and excellent fit. Frequency Response: 12 ~ 38,500 Hz Impedance: 50Ω Sensitivity: 106dB Cable 1: 3.0m (single-sided, left), 6.3mm stereo standard plug (straight) Cable 2: 1.2m (single-sided, left), 3.5mm stereo mini-plug (straight) Please ask if you have any questions in the comments.