UPDATE:I bought the Xl size of this overshoe and it fit over my size 13 4e shoe with room to spare. Much lighter than the 2xl size and more suitable for extended use. In the picture above, the sizing chart recommends that the xl size fits up to a size 13, but you could squeeze in a size 14 if needed.
ORIGINAL REVIEW: I usually wear a size 13-14 extra wide shoe (4e). The size i bought was designed to fit a a size 12.5 to 14 shoe (size 2xl).
These are big. They fit over my shoe with a lot of room left. I could see a size 15 shoe comfortably fitting in these in fact. The base is very roomy and tall. I think these were designed to fit over a workboot with a tall (Steel) toe and not simply a sneaker/shoe.
They are heavy and i would have a hard time recommending these for an entire workday. I usually wear them for a maximum of 2hours at a time and that is fine for me. If you are moving a lot, the weight of this is going to be a significant hindrance. It was a bit strange walking around with all that bulk at first, but i have gotten accustomed to it. I havent fallen or stumbled yet, and to be honest, its a bit surprising, because i stumble a lot. Unlike other overshoes, the sole is solid.
No regrets for me, but consider your needs and usage before purchase