Product review (5 stars): No More Bouncing Washer!
I've had an LG front load washer and dryer for a few years and had no problems until we moved to a new home with a second floor laundry. When the high speed spin cycle started, I felt the whole house shake!  These really did the trick, bought two sets to keep the washer and dryer the same height.  I was skeptical and they are expensive for what's actually there...but they really do work!