Product is awesome but I read alot of reviews saying it runs large. I disagree. I'm an 8 1/2 measured. When I wear flats I usually wear an 8, heels 8 1/2 and boots I usually get a 9. Due to the reviews I ordered an 8, it was to snug and I only had on regular socks. I'll probably exchange for a 9. I reccomend going to a retail store and trying a pair on to make sure you are getting the correct size.