【Cisco IP Phones Compatibility】This wired office phone headset is ONLY COMPATIBLE with Plantronics M10, M12, M22 and MX10 Amplifiers or Some Specific CISCO IP Phones models 7931G 7940 7940G 7941 7941G 7942 7942G 7945 7945G 7960 7960G 7961 7961G 7962 7962G 7965 7965G 7970 7970G 7971 7971G 7975 7975G 6821 6841 6851 6861 6871 6921 6941 6945 6961 7811 7821 7841 7861 8811 8841 8845 8851 8861 8941 8945 8961 9951 9971. | 【Phone Compatibility Guidance】NOT for Cell Phones and Computers. IT ONLY WORKS FOR SOME SPECIFIC CISCO PHONE MODELS LISTED IN DESCRIPTION (include but not limited). Not compatible with Cisco Spa phone series. For other phones, pls contact us for Compatibility Guide or Advice. | 【Crystal Clear Calls】The Cisco Headset with RJ9 jack is ergonomically designed to help call center professionals handle busy calls with ease. It features a Noise-Cancelling Microphone to reduce most background noise for crystal-clear conversations, Plus Acoustic Shock Protection to protect your hearing. | 【Ultra Comfort】 Super lightweight landline Cisco headphone with adjustable headband to fit all head sizes, high quality soft leatherette ear cushion to enhance your wearing comfort during long calls. Keep your hands free for a better communication experience. | 【2-Year Warranty & Super Durable】Callez offer 45 days money back & 24-month worry-free guarantee. Professional Mic Mute / Volume Control built in. Precision design, High-quality plastics, uni-body headband construction, high quality microphone makes this Call Center Headset for Cisco Telephone sturdier and more durable.