Leave it to Park Tool to decide the industry needs a better tool than the manufacterer has produced. The stock Shimano version of this tool is constructed of plastic and will not allow you a great deal of torque without rounding off the edges of the tool with repeated use. In contrast, the BBT-10 is made from investment cast steel and is considered shop quality.
It is designed to remove and install the adjusting caps on Shimano Hollowtech II crank and bottom bracket systems. Both the length of the handles and steel construction provide the strength and leverage needed to remove seized caps as well as installing and removing non-seized caps during standard operation.
Park Tool should have built this years ago when Hollowtech II first emerged. This is the no BS, git er done, shop version of the plastic tool that is commonly used. The wing nut design gives you a lot more leverage than is required for an adjusting cap, which makes using the tool a pleasure when compared to the circular plastic version. There's also a cut out section in the center that fits an allen key- don't know why you would need that, unless a cap was really stuck on a spindle. I ended up applying a little bit of chain lube to that part. Then with my finger pressed against it and my other hand flicking the wing nut portions, I can screw/unscrew the cap in a few seconds. Thumbs up to Park Tools on this one.
Pros: The best tool out there for the task