Voistek A2H20DU10P Dual Ear Call Center Telephone Headset with Noise Canceling Microphone for Nortel Cisco E20 Polycom 335 VVX400 Digium D40 D70 Altigen 500 720 Comdial Aastra Shoretel and Starleaf Office IP Phones See Compatible Phone List (PARTIAL) in Description, DO NOT BUY IF YOU CAN NOT FIND YOUR PHONE MODEL IN LIST, CONTACT US FOR COMPATIBILITY GUIDE ON YOUR SPECIFIC TELEPHONE MODEL IF NEEDED. Direct connect over the head RJ headset,no additional amplifiers or adapters required, most easy setup HANDS FREE headset solution for Most Standard Telephones Equipped with Modular RJ Headset Port. Superior Call Center quality headset FOR DESK PHONE, excellent sound quality, lightweight, durable and comfortable for all day use Noise canceling microphone to reduce background noise and Acoustic Shock Protection circuit to protect your hearing. Noise canceling microphone to reduce background noise and Acoustic Shock Protection circuit to protect your hearing.