1 What does Nickel or Black mean? - This refers to the color of the connector shell.

2 Type of Face Plate? - Bulkhead face plates will have HDMI on the front and HDMI on the rear.

3 What does D Series, Keystone and DB9 mean? - This simply refers to the connector mounting holes used in the plate. The D Series type is a 3 hole design and connectors mount to the plate with machine screws. The Keystone type plates have Keystone holes and the connectors snap in. The DB9 type plates have DB9 holes and mount with machine screws.