I have to admit I was skeptical that this rug pad was going to work seeing how many ripples formed in the rug that I placed on my wall to wall carpet no matter how many times I tried to adjust it. This carpet on carpet really did the trick!  It was a little difficult to adhere  given my large rug size and it was a two person job.  I wish directions would have been included in the packaging but thanks to other reviewers advice, we got it down properly.  After a month of use, it still looks great and is adhering nicely.  Some problem occurred with shipping and it  was not 2 days as promised and apparently a mix up with Fed Ex.  It took 8 days to arrive and was shipped from the same state!