Plantronics CS50 Wireless Headset Features Range up to 350 feet away for maximum mobility DECT technology provides better audio, eliminates interference from Wi-Fi networks Up to 9 hours talk time Secure over-the-head binaural headband provides all day comfort Premium wideband audio quality, noise-canceling microphone One-touch call answer/end, volume up/down, mute, and flash controls Smart power management system optimizes for range and talk time New headsets can subscribe to a base by simply docking the headset Compatibility Yealink SIP-T27G, T27P, T29G Yealink SIP-T40G, T40P, T41S, T42G, T42S, T46G, T46S, T48G, T48S Package Includes Plantronics CS520 Wireless Headset Yealink EHS36 Wireless Headset Adapter