When an ogre puts us on, we grow to the size of his feet. When little Tom puts us on, we shrink to the size of his feet. We can be worn by anyone, and we will take you over fields and forests in a single bound.
A word of caution, though. Don't take too many steps, because you're going to feel as tired as if you traveled the whole distance on your own two feet.
Tom's Seven League Boots in Tom Thumb, Blue Fairy Book. Illustration by Gustave Dore.