This item is great for stretching boots, obviously, duh, sorry.  It will stretch what others won't as they are made for "lower" sized shoes.  The plastic inserts are especially helpful in problem areas, near the great/big and little toes and others.  Solidly made. [The only reason I don't give it five stars is a problem I had with Heartland America, but that's irrelevant here].  They had the best price on it.
If you have a problem with boots this is probably the way to go.