The CS500 series is setting a standard for wireless desk phone communications. Audio controls volume/mute at your fingertips. Multitask hands-free up to 120 metres. Conference in up to three additional headsets. Noise-cancelling microphone reduces background noise interruptions Enhanced Digital Signal Processing. Up to 9 hours of talk time. DECT technology provides better audio. Advanced wideband audio using CAT--IQ technology for high definition voice.