Featuring dual high-definition microdrivers, the SE425 uses a dedicated tweeter and woofer for an accurate and balanced sound. Detachable cable with formable wire enables easy replacement and secure, comfortable fit. Sound Isolating sleeves in multiple sizes provide up to 37dB of isolation. Comfortable sound-isolating sleeves block up to 37dB of ambient noise. Sound-isolation technology prevents outside noise from interfering with your listening experience, whether onstage or on the go. Because every ear is different, the Fit Kit includes three sizes (S, M, L) of the flex and black foam sleeves as well as one pair of triple flange and one pair of universal fit yellow foam sleeves. A good seal is key to optimizing sound isolation and bass response as well as maximizing comfort during extended wear. A durable and compact carrying case is included to provide a convenient, tangle-free solution to store and travel with your earphones. An 1/8" (3.5 mm) to 1/4" converter for all Shure earphones that offers a solution for home stereos or other applications with 1/4" jacks.