Product review (5 stars): If you bought a used KitchenAid or Whirlpool dishwasher and ...
If you bought a used KitchenAid or Whirlpool dishwasher and didn't get brackets, you will need these to keep the unit from tipping forward.  You just slide them in to the slots on your dishwasher and secure them to the bottom of the counter. Installation took 2-3 minutes. PS - Make sure to level your dishwasher before securing to the counter.. If you don't have a level just pay attention to whether the racks tend to move forward or backwards on their own and adjust accordingly.