From Nikon:
The following cameras can be used to update UT-1 firmware.
* Only the camera(s) indicated above can be used to update UT-1 firmware.
* Firmware updates can be performed for you at authorized Nikon service centers.
Modifications enabled with firmware Ver. 2.3
Download: Communication Unit UT-1 Firmware Ver. 2.3
B&H carries the Nikon Communication Unit UT-1.