Koss KC/25 Full Size Stereophone (Black) High Fidelity Stereophone Utilizes An Anisotropic Magnet and 1.4Mm Mylar Element For Deep Bass and Treble Clarity Closed Leatherette Ear Cushions For Maximum Isolation and Deep Bass Interchangeable Slings and Pivoting Ear Cups For Personalized Fit Freq Resp: 20 Hz-18 Khz Closed leatherette ear cushions for maximum isolation and deep bass. Interchangable slings and pivoting earcups for a personalized fit. Straight, dual entry 4 foot cord Deep bass and treble clarity