I can't help but notice that other people give this one a star and say they are "too small" or "useless". According to the product description, it is 1 mm. I don't know what people were expecting but 1mm is 1mm. If you don't know what 1mm is, it's up to you, not the manufacturer of the product. Don't turn them over because you don't know the size of a mm. I know the US doesn't use metric units, but legally you should know what you need before you order a product, get what you ordered, and then fret that you didn't know what you ordered.