1.Adjustable headband 2.Inline with volume and mute controls RJ headset 3. Use: call center Connect: RJ 4. New design Comfort and Stability. The DuoSet headset has two configurations, which allow you to find the perfect fit for your headset applicationDesigned for phones that have a direct headset connectionFreedom of Movement. When your day is filled with one phone call after another, opt for the comfortable and stable over-the-head configuration; other days when you're answering the phone, using the computer, and dashing out to meetings, rely on the unobtrusive, easy-on over-the-ear headset configuration. Either way, your hands are free for multitaskingOver-the-Head Stability or Over-the-Ear Convenience for the Busy Office Professional.Superior Sound Quality from the Leaders. Plantronics' superior voice tube design with patented SoundGuardPlus and Call Clarity technology contributes to the DuoSet headset's excellent sound quality

Driver Unit                       2×30mm Frequency Response    20-20kHz Impedance                        150  ohm Sensitivity                         125dB Max input power              10mW Plug                                RJ11Cord Length                   1.8m Coiled cable