Correct use:
tear a layer of laminating film and stick it on the heel (as shown in the figure)
it cannot be seen from the outside and will not affect the appearance of shoes.
I especially recommend it to buy shoes. I always feel that it is half a size larger, or I will kick my feet ~

the edge of the product is smooth, very soft, not hard,
can effectively prevent foot wear

I bought bigger shoes, too adjust shoe size