Adapter Converter RJ9/RJ10/RJ12 4P4C Polycom Avaya 2400 4600 series Headset/Handset Plug mobile phone 3.5mm plug headset to RJ9|phone ford|phone webcamphone ethernet - AliExpress
VT EHS13 for Polycom( to DHSG) and VT/Jabra DECT headsets
Polycom Compatible VXI VoIP Wireless Headset Bundle with Electronic Remote Answerer (EHS) included | SoundPoint® Phones: IP 335, IP 430, IP 450, IP 550, IP 560, IP 650, IP 670, VVX300, VVX500, VVX310, VVX600, VVX400, VVX1500, VVX4