COMPATIBILITY | Yealink YHS series headset is a professional analog wired headset, can be directly connected to the landline telephone headset. These 4 extension headsets are designed for Cisco phones.✅Compatible with Cisco - 8800/7800/7900/6945 | Runs Right Out of the Box | A QD (Quick Disconnect) to RJ9 plug-and-play office headset makes the connectivity to Cisco IP phones at ease. Perfect match with Cisco desk phones gives you optimized audio quality. | Noise-Canceling Microphone | The microphone technology for Yealink headsets allows for the most reduction of outside noise, so listeners can focus more on the desired sound at hand, the nearby talkers are protected with most call privacy as well. | High-Quality Audio Experience | Made for calls, YHS36 RJ9 headset is kitted out with wideband HD audio technology and passive noise cancellation that ensures a richer and clearer conversations, eliminates background noises as well. | All Day Comfort | The ultra-lightweight materials and bio-mimetic protein-based leather ear cushions make your head and ears feel relaxed. Its ergonomic design enables the phone headsets comfortable enough for long conference calls and all day use.