All-in-One: Under the telephone accessory deck hosts Plantronics top-of-the-line A20 amplifier, cord management, DuoSet™ convertible headset, on-line indicator and headset stand. Easy Adjustment : Audible and visual cues simplify the adjustment of incoming and outgoing volume, tone control and mute DuoSet™ Headset: Convertible for either over-the-head or over-the-ear use with new conformable earloop Improved Sound Quality: Unique SoundGuard® Plus and Call Clarity™ technologies for superior sound Easy Installation: Sets up in minutes with plug-and-play automatic conifguration and seamless telephone integration