Blackmagic Design DeckLink Duo 2 4ch SDI Playback and Capture Card BMD-BDLKDUO2 DeckLink Duo 2 takes up only one single PCI slot in the computer, High performance 4 lane Generation 2 PCI Express DeckLink Duo 2 can also capture and playback at the same time, and also includes a reference connection for black burst/tri-sync Each SDI connection is completely independent, meaning that each of the 4 connections can input or output entirely different video standards and content streams, all at the same time. 4 independent channels that can be assigned to either record or playback in any combination, all on a single plug in PCI Express card