The brackets I received were made well but I had to shim the upright pieces C to keep them from wobbling in the bracket. I also cut the pieces marked A, which I also had to shim, about 18 inches longer to give the wood rack more stability. The lumber I used was a cheap grade of 2x4 not pressure treated which accounts for the shimming.  Personally I'd rather have the slots in the bracket this size than too small.