Comdio Corded Headset Headphones Ear Phone + Volume Mute Control for Nortel Networks Nt Nothern Telecom Meridian PBX Norstar M7208 M7310 M7324 Elite DTU Series Avaya Lucent Voip Ip Telephone (Binaural CH201VA5) 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 Shirt clip included,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.