Audicom PC Headset Adapter Computer Stereo Headphone Dual 3.5mm to Phone Rj9/Rj10 Phone Jack Converter for Toshiba Aastra Nortel Nec Mitel ShoreTel InterTel Talkswitch Telephone IP Phones(PC35-STAA) PC Stereo Headset Adapter Converts Dual 3.5mm to RJ Plug.Adapter with two ports:one for Speaker jack and the other one for Mic Jack.Please note to plug the headset into correct jack,if the headset doesn't work, exchange the position of your 3.5mm headset jack to plug into the adapter. Still get great quality stereo sound from headset via this adapter All functions on headset and phone would function same Easy Setup, Plug and Play ONLY WORKS FOR SOME SPECIFIC PHONES. PLEASE SEE COMPATIBLE PHONE MODELS LISTED IN DESCRIPTION BELOW.