With the speed at which children's feet grow and the constant demands on time and energy as it relates to keeping them in comfortable, quality shoes that fit, this device has been a lifesaver.  My daughter has had a wide foot and high instep since birth.  Like most children, she also had two slightly different sized feet.  Rather than drive to a shoe store to have her properly re-measured (which could end up with three different sizes at three different shoe stores - even if the same chain - I can pull this out of the closet weekly if I want to check on how those piggies are growing). Well worth the investment.