If I could give this a 3.5, I would.  I use these w/flats and heels.  It would be great if it stretched vertically in addition to horizontally.  It does not fit in long ways, but I mainly purchased it to widen shoes.  It's pretty sturdy.  I've used it to stretch several pairs of shoes now.  I bought 2 so that I wouldn't have to do one shoe at a time. Who has time for that when it takes a good 3-4 days to get a really good stretch.  I really like how you can place the silver bumps in problem areas, great idea!