D2 and GXP Products follow the same compatibility guide with the exception of lifters. The D2 was not designed to function with a lifter.
Standard RJ9 headsets:
The headsets listed in GXP21xx/17xx headset compatibility document are generally compatible with
GRP261x series as well. However, not all headsets in GXP21xx/17xx headset compatibility document are
individually tested on GRP261x due to headset availability. Here is the GXP21xx/17xx headset compatibility document for reference:
For direct documentation on the GXP series use this link to view the Grandstream recommended headset devices.
For information on pairing a Bluetooth headset and using hands-free mode, please click here.