Comdio H203VAB Corded RJ Headset with Flexible Noise Canceling Mic + Volume Mute Control for Aastra Adtran BT Alcatel Lucent Avaya Ascom Audioline Elmeg Gigaset Interquartz Office Telephone IP Phones 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. Direct connect over the head headset, No additional amplifiers or adapters required, Most easy setup headset solution. Superior quality sound with the flexible adjustable noise cancellation microphone. Super Lightweight, Super Durable Headset with Comfortable ear and mic cushions. Professional Mic Mute / Volume Control built in.