The Cisco Headset Hookswitch Control (HHC) enables Electronic Hookswitch (EHS) functionality to work with Cisco 7900G phones manufactured after September 2007 and Jabra GN9350, GN9120 EHS and GN9120 Duo EHS wireless headsets (LR included). Simply "plug and play" to hear ring tones, answer and end calls, adjust volume, or even mute calls from your headset's integrated controls, all up to 300 feet away from your phone! The Cisco HHC EHS works with the following Cisco 7900G products manufactured after September 2007: Cisco 7975G, 7965G, 7945G, 7962G, and 7942G only. The Cisco HHC EHS converts from the HHC standard used in Cisco phones to the DHSG standard used in Jabra headsets — and vice versa — to allow you to maximize the benefits of both your wireless headset and Cisco Unified IP phone for expanded efficiency and productivity.