What adapter do I need to connect a Cinema HD Display Model 8536 to a MacPro 2.1, or is it even possible?
The picture you've posted is of an Apple Display Connector, as mentioned by @RazOrEdge. If the graphics card on your Mac Pro has DVI outputs, you'll need a DVI - ADC adapterThe DVI doesn't fit the MacPro. I've attached a photo of the connector.