Adapter cable included & work with Avaya IP 1608, 1616, 9601, 9608, 9608G, 9610, 9611, 9611G, 9620, 9620C, 9620L, 9621, 9621G, 9630, 9630G, 9640, 9640G, 9641, 9641G, 9650, 9650C, 9670, 9670G, J139 J159 J169 J179 J189 series phones. Offer 2 years warranty against manufacturer defect and workmanship. Suitable for use as hands free call center Headset, office phone Headset, telephone headset, telemarketing Headset. Fit any head size, adjustable headband. Comfortable and reliability. Super soft leather ear cushion and foam cushion. Comes with a Plantronics Style QD connection, so compatible with alongside any Plantronics products. Enhanced noise canceling microphone filter background noise. Mic boom 330 degree rotation offer optimal convenience, HD voice audio quality perfect work with you all day. Clear call quality, perfect sound volume moderate and comfortable. Broad band audio frequency makes more natural voice. Hearing protection with active protection technology.