【Compatible with CISCO IP Phones】This Phone headset works with most Cisco phones with RJ9 headset port, such as 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 or M10, M12, M22 and MX10 Amplifiers. NOT compatible with Cisco SPA phone series. | 【Crystal Clear Calls】 This high sound quality Phone Headset with Microphone enables clear and natural communication, features Noise Cancelling Microphone to reduce background noise for Call Centers. Acoustic Shock Protection Circuit to protect your hearing. Mono headset can be worn on either side and you can still communicate with your colleague while wearing it. | 【Ultra Comfort】Lightweight Wired Hands-free Telephone Headset for Cisco Desk Phones with adjustable headband to fit different head sizes, high quality and soft leatherette ear cushions enhance all-day wearing comfort. Professional Mic Mute/Volume Control built in. Ideal for Call Center, Office, Home, Business, Telephone Counselling Services. | 【Quick Disconnect Cord & Super Durable Design】A QD (Quick Disconnect) to RJ9 plug-and-play makes the connectivity to Cisco phones at ease and enables you to walk away from the desk without taking headset off. Precision design, quality plastics, unibody headband construction, flexible mic boom makes this office phone headset with RJ9 jack sturdier and more durable. | 【2-Year Warranty & Compatibility Notes】Callez offers 45 days money back & 2-year worry-free guarantee. THIS TELEPHONE HEADSET DOESN’T WORK FOR SMARTPHONES AND COMPUTERS. ONLY COMPATIBLE with some specific CISCO phone models listed in description (include but not limited). For Other Phone Models, Pls contact us for Compatibility Guide or Advice.