Sennheiser Cx 300S In Ear Headphone With One-Button Smart Remote - Red Boost your sound with Sennheiser?s CX 300S earphones which offer amazingly detailed sound reproduction and enhanced bass response thanks to Sennheiser?s transducer technology. S, M, L) to choose from. A Smart remote enables you to play/pause music and take calls across all devices. Precision German engineering ensures excellent audio clarity, so you will hear every detail of your music Product Note : If the size of the earbud tips does not match the size of your ear canals or the headset is not worn properly in your ears, you may not obtain the correct sound qualities or call performance. Change the earbud tips to ones that fit more snugly in your ears One button inline smart remote makes it convenient to play and pause music and take calls without needing to fumble with your phone Four sizes (XS, S, M, L) of ear adapters are included so you can get an individualized fit for personal comfort In ear design creates a secure fit for excellent reduction of ambient noise so you can relax and focus on the music