Koss KDX100CHR Chrome Noise Isolation Earbud Stereophones - (CHROME) (Discontinued by Manufacturer) Delivers Accurate Acoustical Reproduction and Isolation Typically Found In More Expensive, Closed-Style Stereophones Features A Dynamic Element That Is Positioned Just Outside The Ear and Connected To A Tubular Port Structure That Is Inserted On 1 Of 2 Provided Cushions: A Fluted Silicone Or Conforming Memory Foam Cushion Freq Resp: 10 Hz-20 Khz Imp: 16_ Connectivity Technology: Wired