Got a pair for me and for my wife from Santa for Christmas gifts. I wear a size 10 hiking boot and ordered the large. My wife wears a size 7 1/2 boot and ordered hers in a small. We've both used them to walk the dog on extremely icy asphalt trails around our sub-division. You'd never know there was ice at all with them on. With them off, you can barely stand in one spot without falling. Hiking over 5 miles so far and they have never budged on the boots. They stretch on over the boot sole with just a little bit of a strong stretch. As long as the ice is around, we just change in and out of the boots leaving the Stabilicers on the boots. They fit totally true to size, do not come off and work flawlessly. Don't even consider anything else but these. They're fantastic!