Since it is extremely fine, it is measured with a micrometer to confirm the size. The size is very accurate. It is tough to turn it once because it is just arranged in a container. I think that it should be a container of a method to be put in a hole.
I used pinnipes of Annex, with three drills, but I also wanted a spare and the same size as the size difference I bought it. Right now, I am working to drill out the part of the hole of the cotton pearl that is blocked. There is no problem with the same 1 mm in Annex, but here, pulling the drill comes with cotton, the hole closes more than the original, even a thin needle will not pass. Is the smoothness of the drill surface different? Or did you choose a product and made a mistake? It's a set, so if you fail, it's big. As I mentioned in other reviews, I think that I will buy next time where I am selling individually.