Comdio CH103VA2 Corded Call Center Phone Headset + Volume Mute Control for AASTRA, Allworx, Altigen, Avaya, NEC, Nortel meridian, Norstar, PolyCom, ShoreTel, Adtran Digium and Talkswitch Telephones with RJ9 jack Direct connect over the head headset headphone, No additional amplifiers or adapters required. Superior quality sound with the flexible adjustable noise cancellation microphone. Most easy setup headset solution, Comfortable ear and mic cushions, Super Lightweight, Super Durable Mic Mute / Volume Control built in. ONLY WORKS FOR SOME SPECIFIC PHONES. SEE COMPATIBLE PHONE LIST IN DESCRIPTION, BUY THE ITEM TODAY IF YOU HAVE ONE OF THE PHONE MODELS LISTED BELOW. If you still can't find your phone model, pls feel free to send email to us, and our headset experts will check the compatibility.