Koss Pro4S Full Size Studio Headphones, Black with Silver Trim Design Your Music with these professional, unbiased, fine-tuned Studio Headphones Aluminum Construction - comfort and durability meet in this lightweight headphone Dual Choice Entry - choose either left of right cord entry and monitor through multiple headphones with a unique pass-through feature Contour Sealing Cushion - the unique D-profile closes gaps around the ear, improving comfort, fit, isolation, and sound Koss SLX40 Dynamic Element precisely tuned to accurately convey the sound produced in the studio. Connectivity Technology: Wired Detachable