Hearing Protection & Quick Disconnect: With built-in anti-acoustic shock circuit, the corded telephone headset for Cisco phone will protect users against acoustic injury caused by sudden sound burst. Quick Disconnect feature provides walkaway convenience, enabling user quickly leave for a short time or switch to other sound equipments. Great Durability: Quality materials are used to ensure the ultra durability of Cisco phone headset, the reinforced cord is built to withstand the demanding environment and is protected against office chair wheels, sharp objects on daily use, and the durable construction allows headset for a long time use. Headset Work with Cisco Phones: This Corded telephone headset with microphone noise canceling is only compatible with Cisco IP phones with RJ9 headset jack, such as 6921, 6941, 6945, 6961, 7821, 7841, 7861, 7931G, 7940, 7941G, 7942G, 7945G, 7960, 7961, 7961G, 7962G, 7965G, 7970, 7971, 7971G, 7975, 7975G 7985G, 8811, 8841, 8845, 8851, 8861, 8865 and 8900, 8941, 8945, 8961, 9951, 9971, etc. Please do not buy it for CISCO SPA SERIES PHONES. Luxurious Comfort: Being lightweight and simple, MKJ headset for phones landline office is comfortable enough to wear for an extended period of time, with no pressure on your head even for a long time wearing. An adjustable headband fits different head sizes and the gooseneck microphone boom offers an accurate talking position. What's more, a single ear headset can be worn on either side and you can still communicate with your colleague while wearing it. Outstanding Sound Clarity: Advanced voice technology ensure phone headsets for Cisco phones deliver a crystal-clear voice for easy communication, plus a noise-canceling microphone filters out sharp background noise and lets the customer hear your voice clearly, these wired headphones with microphone are ideal for noisy environments, such as call center agents, telemarketing offices, home phone job users, customer service, etc.