ONLY Compatible with Plantronics M10, M12, M22 & MX10 Amplifiers or CISCO IP phone models : CTS 500 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 | This is the CISCO Cable that connect any Plantronics H & HW series headset with most Cisco 6900, 7800, 7900, 8900, 9900 series IP phone (as long as it has a RJ9 modular Headset Jack). | ONLY WORKS FOR SOME SPECIFIC PHONE MODELS LISTED ABOVE. Not compatible with Cisco Spa phone series. For other phones, pls contact us for Compatibility Guide or Advice. | NOT FOR Jabra GN headsets as the photo shows. | COMPARE with Plantronics Cisco Cable 26716-01 cord