GRANDSTREAM GXP2140 Enterprise HD Voice IP Telephone, color high reso
GXP1760W EHS port - GXP17xx Series mid-range IP phones -
Converter Adapter | Converts RJ-9 to 2.5mm for phones that have a 2.5mm jack., (2200-11095-002) | Use with APP-50, APP-51 EHS for Polycom, Connecting telephone devices to 2.5mm headset mini jack
EHS Contact Center Cables/Lifters - Headsets Direct
DHS14 EHS Cable For Adapt 30 – Discover Headsets
Fanvil EHS headset adapter for JABRA (Jabra PRO 920, PRO 9450, PRO 94