Not this:
http://www.amsperformance.com/cart/i...ioner_tool.jpg
But the tool used to twist the tensioner itself, it fits into the two holes:
I've used a few homemade ones, and while they got the job done, I'd like to find one that the pins don't bend on and you can actually fit a wrench on the nut once its twisted. I think MHI makes a tool for it, but I've heard other tools are out there. What do you use?