The Sennheiser CC 510 with CSTD 08 Bottom Cable headset uses Ultra Noise Cancelling technology to eliminate background noise, so you can make yourself heard perfectly, while the ActiveGard technology protects your ears against sudden loud noises. The adjustable microphone is compatible with most telephones and provides excellent speech quality. The CC510 has been ergonomically designed for optimum comfort levels with a strategically padded adjustable headband and soft foam ear pads, making it comfortable to wear even for extended periods of time. This model is also available in a binaural version