Product review (4 stars): Perfect solution
This was the second set of anti-vibration pads I bought for a front-loading washer in our 2nd-story laundry room.  The first set (<a data-hook="product-link-linked" class="a-link-normal" href="/Washing-Machine-KE-Shake-Away-Plus-Pads-Vibration-Pads-Super-Duty-Version/dp/B001171TZG/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">Washing Machine KE Shake Away Plus Pads Vibration Pads Super Duty Version</a>) did a really good job reducing vibration and noise but would not stay under the washer feet.  These Anti-walk Silent Feet do a great job.  Vibration and noise is reduced significantly, about to the level of a top-loading washer.  With the indentation, the washer feet stay put.  They are designed to not slide around, which makes installation on the back feet a bit tricky, but they stay in place and that's a good thing.  I have had these for about 9 months and I am pretty satisfied.  The first set of pads that I had were quieter with better anti-vibration but these are a better all-around solution.