Shure SE110 Sound Isolating Earphones - White Sound Isolating Sleeves - The role of the included sound isolating sleeves is twofold - blocking ambient noise and ensuring a comfortable customized fit. Because every ear is different, the Fit Kit includes three sizes (S, M, L) of the Flex and Black Foam Sleeves. Experiment with the size and style that creates the best fit for you a good seal is key to optimizing sound isolation and bass response as well as maximizing comfort during extended wear An included 3-foot cable allows you to tailor your experience depending on activity and application - Detachable Carrying Case - A durable and compact carrying case is included to provide a convenient, tangle-free solution to store and travel with your earphones Speaker Type - Balanced MicroSpeaker Sensitivity (1mW) - 113 dB SPL/mW