Plantronics PTH200 (also referred to as part# 61935-11) is a modified version of the TriStar in-ear headset with voice tube microphone, made for use with the Spectralink system and for use with the Nortel wireless IP handset WLAN 2210 and 2211. The special shielding in the cord mitigates a buzz sound which would otherwise occur with a standard Plantronics headset. The PTH200 comes with the necessary cord to connect to your phone so no additional parts are required. Also comes with clear voice tube microphone and 4 different sizes/shapes of earbuds so you can customize the fit in your ear. If do not have a Spectralink system or a Nortel WLAN 2210 or 2211, please do not order this item. Covered by 2 year factory warranty.