My son is 13 months old and is walking but has very wide and chubby feet.  Finding shoes that fit him well is incredibly challenging.  After several attempts to purchase other "so-called" adjustable sandals, we gave these a try.  Much to our surprise, these met and exceeded all of our expectations as they are truly fully adjustable.  The entire top of the sandal is adjustable.  You can make the entire shoe as looose or tight fitting as is comfortable for the child.  My only regret is that I didn't find these sooner...and order them in every color.  My son is a 5 Toddler shoe size and the 5M US Toddler we ordered are very true to size.  No need to order a size up or down.  The sole is also very solid and not slick on the bottom, which is nice for me having an early stages walker.  I don't see these shoes wearing out the way we have seen other sandals perform since he will wear them almost daily.

UPDATE:  My son wore these shoes the entire summer last year and outgrew them before they started to show any real wear.  I just purchased another pair in a larger size for this summer. I could not be happier with these shoes!