Apple M8661LL, 661-4252, 661-2626, 661-3056, 825-6779-B, A1006. DVI to ADC Display Adapter and Power Supply.
Allows you to power an ADC Display with a DVI port. Works with all ADC displays, such as these or these, and can be used with most any Mac with USB whose video out port can be adapted to DVI with an additional adapter.
These include most G4, G5, Mini, Mac Pro and Macbook Pro computers. Please research for your exact computer.