PHONE HEADSET FOR CISCO PHONES: ONLY compatible with Plantronics M10, M12, M22 & MX10 Amplifiers and Cisco IP phones 6851, 6921, 6941, 6945, 6961, 7811, 7821, 7841, 7861, 7931G, 7940, 7940G, 7941, 7941G, 7942, 7942G, 7945, 7945G, 7960, 7960G, 7961, 7961G, 7962, 7962G, 7965, 7965G, 7970, 7970G, 7971, 7971G, 7975, 7975G, 8811, 8841, 8845, 8851, 8861, 8941, 8945, 8961, 9951, 9971. NOTE: THIS TELEPHONE HEADSET IS NOT FOR CELL PHONES AND COMPUTERS. | BUILT TO LAST AND PURCHASE NOTES: The durable structure and reinforced cord ensure this wired telephone headsets to withstand heavy use in busy working environment. NOTES: 45 days money back & 2 year warranty. NOT COMPATIBLE WITH Cisco SPA phone series; ONLY FOR SPECIFIC PHONE MODELS LISTED IN DESCRIPTION (for phones not listed, pls contact with us for compatibility advice, to avoid buying the wrong headset). | CRYSTAL CLEAR CALLS: Design with noise cancelling microphone and flexible boom mic, this professional office phone headset provides crystal-clear communication even in noisy work environment. Acoustic Shock Protection protects our hearing carefully from sudden sound burst. | ALL DAY COMFORT: This hands free phone headset with microphone assists you to work more comfortably and reduce pain on your neck and shoulder. Adjustable headband will fit all head sizes and wear firmly. The soft and high quality leatherette ear cushions and super lightweight design increase all-day wearing comfort. | EASY AND CONVENIENT TO USE: Plug this telephone headphone directly into your Cisco desk phones without additional amplifiers or adapters. Including volume control and microphone mute switch onto the cord, this RJ9 headset is customized for CISCO landline phones in Call Center Service, Conference Calls, Telemarketing, Home and Office etc.