Wantek Wired Telephone RJ Headset with Flexible Noise Canceling Mic for Aastra Shoretel Nortel Cisco E20 Polycom Digium Altigen Comdial & Starleaf Office IP Phones(H220P003A) Only works for some specific phones with Standard Modular RJ Headset Port. SEE COMPATIBLE PHONE LIST IN DESCRIPTION, BUY THE ITEM ONLY IF YOU HAVE ONE OF THE PHONE MODELS LISTED BELOW. Direct connect over the head telephone headset, No additional amplifiers or adapters required, Most easy setup headset solution. Superior Call Center quality sound headset with flexible adjustable noise canceling microphone. Super Lightweight, Super Durable Headset with Comfortable ear and mic cushions for all day use. Shirt clip included. NO Mic Mute & Volume Control built in.