This headset training adaptor splits your RJ11/RJ9 headset port on your phone into 2 ports enabling 2 corded or cordless headsets to be used at one time. The adaptor also has a mute switch on both channels so you can switch off the microphone for the trainer and should they need to take over the call, a quick press of the button and they can speak to the customer. This cable is not brand specific and will work with all headset brands such as Xenexx, Plantronics, Sennheiser and GN Netcom. Works on most phones with a standard headset port except Cisco. There is also a Cisco variant available.