RJ9 Headset Compatibility: This corded telephone headset with noise cancelling microphone only Compatible with Cisco phones with RJ9 headset jack, such as Cisco 6921, 6941, 6945, 6961, 7821, 7841, 7861, 7931G, 7940, 7940G, 7941, 7941G, 7942G, 7945, 7945G, 7960, 7960G, 7961, 7961G, 7962G, 7965G, 7970, 7970G, 7971G, 7975G, 7985G, 8811, 8841, 8845, 8851, 8861, 8865 and 8900, 8941, 8945, 8961, 9951, 9971. Please see in PRODUCT DESCRIPTION for compatibility guide or contact us directly. | HD Sound Quality: Crystal-clear voice quality is very important, this RJ9 phone headset for office phones delivers clear sound to ensure an effective communication. The noise cancelling microphone blocks out surrounding noise and pick up loud and clear sound which makes you feel that you are having a face to face conversation, such quality headset is ideal for those who are on the phone all day long, such as call center agents, work from home, customer service staff etc. | DUAL EAR DESIGN: Binaural telephone headset for landline phones covers both ears and helps users to concertrate on the call and hear less ambient noise around them, makes them more productivity during the conference call. | Comfortable to Wear: This Corded phone headset compatible with Cisco CP-7821 delivering good sound without hurting your ears. Being lightweight and ergonomic design, plus soft leatherette ear cushion ensures all-day comfortable wearing, also the perfect adjustable headband will fit bigger or smaller heads comfortably. | High Durability: Sturdy yet comfortable office phone headset withstands the most demanding environments. The reinforced, lightweight and stainless steel headband provides high strength to withstand the lasting use.