HPPFOTRS Operator headset accessories HPP-11 Training Adapter for two new training monitor telephone Headset Training Switch Adapter for Nortel Meridican, Norstar, Avaya, Ashtra, Mitel, Polycom, Ge and Other Ip Phone HPPFOTRS Operator Headset Training Switch Adapter Model:HPP-11 Allows for Use of Two Handsets on One Telephone Mute Button Control