All Day Comfort | Designed with replaceable foamy ear cushions, the business headset can softly cover the ear and support long conference calls, the extremely lightweight design enables the phone headset all-day wearing comfortable without pressure. High-Quality Audio Experience | Made for calls, YHS34 RJ9 is kitted out with a high signal-to-noise ratio speaker and independent cavity design. The passive noise cancellation creates a richer and clearer conversation with reduced background noise. Ultra Lightweight Design | YHS34 Lite telephone headset is built for comfort with soft ear cushions and ultra-lightweight materials, the headset is 10%~30% lighter than other professional headsets in the same range. 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. 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.