Attentiono: Not Compatible with CISCO Spa phone series and Models 7911 7912 7811. ONLY Compatible with Plantronics M10, M12, M22 & MX10 Amplifiers and CISCO IP phone models : Cisco IP 6921, 6941, 6945, 6961, 7821, 7841, 7861 Cisco IP 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 | ONLY WORKS FOR SOME SPECIFIC PHONE MODELS LISTED ABOVE. For other phones, please contact us for Compatibility Guide or Advice. | High Sound Quality for Clear Communication: Wideband Sound telephone headset enables natural listening experience, features Noise Canceling Microphone to reduce background noise, Acoustic Shock Protection Circuit to protect your hearing. | Comfortable Headset: Super lightweight office telephone RJ headset with adjustable headband to fit all head sizes, high quality and soft leatherette ear cushion enhance all-day wearing comfort. | Super Durable: Precision design, quality plastics, unibody headband construction, superior quality?microphone makes this call center headset sturdier and more durable.