Shure SE420-K Sound Isolating Earphones (Black) Dual speakers for deeper bass and spaciousness Dual TruAcoustic MicroSpeakers: Dedicated Tweeter and Woofer Sound Isolation Technology reduces background noise better than noise-cancelling headphones, without batteries or added hiss Premium Fit Kit including a selection of interchangeable sleeves for personalized, comfortable fit; 3' extension cable; premium carrying case Modular Cable Design lets users choose different cable lengths to suit different music player locations (armband, pocket etc.)