You only need an SLI bridge if you plan on running SLI with 2 SLI compatible cards on a compatible motherboard. If you are just adding a second card to support more monitors you do not need SLI and therefore require no SLI bridge between the cards.
You only need an SLI bridge if you plan on running SLI with 2 SLI compatible cards on a compatible motherboard. If you are just adding a second card to support more monitors you do not need SLI and therefore require no SLI bridge between the cards.