Comdio CH403A3 Corded Call Center Phone Headset for Avaya Nortel Meridian Norstar Aastra Allworx Altigen Plantronics T20 Talkswitch ESI Doro Hybrex Cable & Wireless Telephones Superior quality sound with the flexible adjustable noise cancellation microphone. Most easy setup headset solution, Comfortable ear and mic cushions, Super Lightweight, Super Durable Direct connect over the head headset headphone, No additional amplifiers or adapters required. NO Mic Mute / Volume Control built in. SEE COMPATIBLE PHONE LIST IN DESCRIPTION, BUY THE ITEM TODAY IF YOU HAVE ONE OF THE PHONE MODELS LISTED BELOW.