Precision T3640 part number for the Rear USB-C optional connector

Hi all,

i have a Dell T3640 - i am trying to find the part number for the USB Type-C Port with DisplayPort Alt-mode (optional connector). This is the little daughter board that fits to the motherboard and gives an optional port at the rear. 

I have found the VGA part - but not the USB Type-C Port

Dell Original Precision T3630 3640 Tower Workstation VGA transfer interface N3VW

Dell Original Precision T3630 3640 Tower Workstation VGA transfer interface N3VW | eBay

This is from the marketing blurb:

1 VGA port / HDMI 2.0 port/ DP++ 1.2 port/ USB Type-C Port with DisplayPort Alt-mode (optional connector)