Recommended Connection
Used cables
TelePhone Code (2 cables)
Controll Code
RJ9
3.5mm
RJ9
3.5mm
KX-UT670
EHS（CS70N）
Handset port [A]
Headset Lifter Jack
RJ9
3.5mm
RJ9
Modular Handset Jack
3.5mm
EHS Jack
Handset port [B]
RJ9
RJ9
Modular Handset Jack
in Handset
Connection which may cause disconnect
Used cables
78333-01 [Plantronics]
Controll Code
RJ9
3.5mm
2.5mm
3.5mm
KX-UT670
EHS（CS70N）
RJ9
Handset port [A]
Headset Lifter Jack
Handset port [B]
Modular Handset Jack
3.5mm
3.5mm
2.5mm
EHS Jack
Headset Jack
Modular Handset Jack
in Handset

Bluetooth Devices (PDF Download)