Product review (5 stars): You need these when having laundry that is not on a cement slab!
My mother in law did not use these and 2 years after having her front loading washer on her main floor actually had to have wiring and drywall repaired that was damaged from all the vibrations. We used these from the start on our washer. 5 months later not even a picture hanging in the laundry room has come off level.