I just purchased a Hayden cooler that I'm planning to install to supplement my existing cooler. I was looking at the cooler lines to the radiator, and I see nothing that indicates the flow direction. In other words, which line is "in" and which one is "out"?

It wouldn't matter if I were simply installing the cooler alone, but I want to install it so that the fluid goes from the tranny, through the stock cooler, then through the auxiliary cooler, and then back to the tranny. A picture with labels would be extremely helpful.

Any advice is appreciated.