Customer service representatives & staff in busy call centers look to this headset for unmatched sound quality & comfort. Twin speakers of the highest quality are mounted on two-way swivels & rest gently but firmly on the outside of the ear, to block out distracting colleagues conversations. Soft cushions ensure the headset stays comfortable all day. Plantronics Sound Enhancement System (SES) gives you the option to enhance the callers voice for even greater clarity. Add a noise-canceling microphone & youll have the best sounding, most comfortable headset available. The Quick Disconnect cord means that you can break away from your caller without placing them on hold. The Encore Binaural Polaris Headset requires a phone system with an existing internal amplifier. If your phone does not have an internal amplifier, we recommend you try our H-Series.