Comdio 2.5mm Call Center Headset Headphone with Mic + Volume Mute Controls for Polycom IP320 IP321 IP330 IP331 SoundPoint Pro SE-220 Zultys Technologies: ZIP 4x4 ZIP 4x5 Telephone IP Phones (H303VP2) 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. Superior quality sound with the flexible adjustable noise cancellation microphone. Direct connect over the head headset headphone, No additional amplifiers or adapters required, Most easy setup headset solution. Super Lightweight, Super Durable Headset with Comfortable ear and mic cushions. In-line Mic Mute / Volume Control built in. For Mobile Phone with 3.5mm headset jack like iPhone Samsung LG HTC Blackberry Huawei ZTE...etc, please check our items: Comdio H103-35M1 or Comdio H103-35M2