I'll admit that I was confused and purchased this item first thinking that it was intended to stretch width AND length (I bought a size 39 boot that feels about 1/2 size too small). That's my bad, if you read the product description carefully you'll see that, but the implication is also that you gain some length when you stretch width. I left these in my ankle-high cowboy boots for like 2 days, and even used some shoe stretcher liquid to try to get the most effect. I didn't notice any improvement in the width, and definitely no improvement in the length; they still pinch a lot. Perhaps if your shoes are of very supple leather or a thin synthetic these will work for you, but I wasn't all too excited.

Unfortunately I've found it pretty much impossible to find a boot stretcher for the length - seems that they only make these for regular shoes! grr.