The attachment for the brick is the set of white and black wires, with connectors on one end that can be sandwiched into the AIU input knobs, and a white plug that connects to the brick. In the picture, there are two sets of white plugs and wires, I only used one. (not sure what the other is for, unless you can plug two bricks into the same input). I do not remember if this adaptor wire comes with the brick or not, however I think it does. You should verify for yourself, as I purchased my bricks over 10 years ago.
In the picture above, there are two bricks, each one powers 2 AIU channels. There is a jumper wire (red & black) between red & black connectors on channel 1, going to channel 2.