You have the wrong questions for this product.because it has nothing to do with fitting.  What it does is help stretch your shoes when they are a tad too tight and it works great.  I have a bottle at work and at home and have used it a lot.  For anyone who purchases shoes and they are just a bit tight in one place this stuff sprayed on that location...put your foot in the shoe and wiggle it around will find some immediate relief.  I have had to do it twice on a really tight fit by my arch, but it does work.