The Decklink Quad 3G-SDI Mezzanine Card for Decklink 4K Extreme 12G from Blackmagic Design is a replacement for the original daughter card that came with your Decklink 4K Extreme 12G PCIe board.

The HDMI ports on this daughter card support HDMI 2.0, as opposed to the ports on the original board, which only supported HDMI 1.4b. The daughter card features two bi-directional optical fiber ports. Replacing your original daughter (mezzanine) card with this one expands your cards input and output capabilities to support HDMI 2.0.