Headphones with detailed sound and enhanced bass Built-in microphone and remote control for call and music control, ergonomic design on the ear for environmental noise isolation and uninterrupted listening. Strong, tangle-free cable for long-lasting hearing enjoyment. Improve your sound with Sennheiser CX 300S headphones, offering incredibly detailed sound reproduction and enhanced bass response thanks to Sennheiser transducer technology. The internal design minimises ambient noise, and the included ear adapter set ensures an individualized fit with four sizes (XS, S, M, L) to choose from. Intelligent remote control allows you to pause music and take calls on all devices.