The original UD-3900 model docking station launched in 2013 offered one DVI video output port and one HDMI video output port.
Based on customer feedback, in February of 2025 we introduced a new version of the UD-3900 that updated the configuration to two HDMI video output ports (and removed the DVI video output port).
If you need to connect a DVI display to the new version of the UD-3900, you can do so by using an inexpensive HDMI to DVI video cable (a cable with a HDMI connector on one end and a DVI connector on the opposite end). An example of such a cable would be this one → LINK
If you need to connect a VGA display to the new version of the UD-3900, you can do so by using a Plugable HDMI to VGA video cable → LINK