This product is made of flexible plastic. When you put a standard sock (mens 1 size fits all) on it, it closes up enough that if you have a wide foot, your foot will not go through. I have a 10EEE foot and in rehab I had a wide sock aid that was rigid plastic and I had no trouble at all. Also, there are sharp corners on this item and you will have to file them or you will scratch your foot and ankle.