The Plantronics CS545-XD Wireless Headset features 900MHz technology and allows you to multi-task from up to 350' away. The headset features fingertip audio controls and allows you to conference in up to three additional CS500 XD Series headsets (sold separately). The convertible headset is lightweight (less than 1oz) and you can choose from three wearing options. The headset's 900MHz wireless technology allows for a high number of available channels and clear conversations. You can select either narrowband mode to preserve talk time or wideband mode for clearer conversations. The noise-cancelling microphone reduces background noise interruptions. Additionally, Enhanced Digital Signal Processing (DSP) offers for more natural sounding voices. A spare battery and charging cable are included to allow unlimited talk time.