Voistek Corded Mono Over the Head Call Center Telephone RJ Headset Noise Cancelling Headphone with Microphone for Cisco 7941 7945 Office IP phones and M10, M12, M22 & MX10 Amplifiers (K10CIS) WORKS ONLY with Plantronics M10, M12, M22 & MX10 Amplifiers and Cisco IP phone models : 12VIP, 30VIP, CTS 500 Cisco IP 6921, 6941, 6945, 6961, 7821, 7841, 7861 Cisco IP 7931G, 7940, 7940G, 7941, 7941G, 7942G, 7945, 7945G Cisco IP 7960, 7960G, 7961, 7961G, 7965G Cisco IP 7970, 7970G, 7971G, 7975G Cisco IP 8941, 8945, 8961, 9951, 9971 Direct connect over the head telephone headset, no additional amplifiers or adapters required, most easy setup headset solution. Superior Call Center quality headset for Cisco Unified IP Phones, excellent sound quality, lightweight, durable and comfortable for all day use Noise canceling microphone to reduce background noise and Acoustic Shock Protection circuit to protect your hearing. DO NOT BUY THIS ITEM IF YOU DON'T HAVE ONE OF THE PHONE MODEL LISTED ABOVE. Not compatible with Cisco Spa phone series, CONTACT US FOR COMPATIBILITY GUIDE IF NEEDED.