ONLY WORKS with M10, M12, M22 & MX10 Amplifiers or CISCO IP phone models : Cisco IP 6921, 6941, 6945, 6961, 7821, 7841, 7861 Cisco IP 7931G, 7940, 7940G, 7941, 7941G, 7942, 7942G, 7945, 7945G Cisco IP 7960, 7960G, 7961, 7961G, 7962, 7962G, 7965, 7965G Cisco IP 7970, 7970G, 7971, 7971G, 7975, 7975G Cisco IP 8811, 8841, 8851, 8861, 8941, 8945, 8961, 9951, 9971 or AVAYA CALLMASTER V VI ONLY COMPATIBLE FOR SOME SPECIFIC PHONE MODELS LISTED ABOVE. Not compatible with Cisco Spa phone series. FOR OTHER PHONE MODELS, PLS CONTACT US FOR COMPATIBILITY GUIDE OR ADVICE. Thanks,

Super Durable: Precision design, quality plastics, unibody headband construction, superior quality microphone makes this call center headset sturdier and more durable. High Sound Quality for Clear Communication: Wideband Sound telephone headset enables natural listening experience, features Noise Canceling Microphone to reduce background noise, Acoustic Shock Protection Circuit to protect your hearing. ONLY COMPATIBLE WITH SOME SPECIFIC PHONE MODELS LISTED IN DESCRIPTION. Buy the item today if you have one of phone models in list. For other phones, pls contact us for Compatibility Guide or Advice. ONLY COMPATIBLE WITH Cisco Unified IP Phones:7940 7940G 7941 7941G 7942 7942G 7945 7945G 7960 7960G 7961 7961G 7962 7962G 7965 7965G 7970 7970G 7971 7971G 7975 7975G 6921 6941 6945 6961 7821 7841 7861 8811 8841 8851 8861 8941 8945 8961 9951 9971 and Amplifier: M10 M12 M22 & MX10 Vista Modular Adapters. Volume control for Speaker and Mute switch for Microphone.