A: needles commonly used today have diameters ranging from 0.25mm to 0.4mm. Except for the difference in the thickness of a single needle, the gap between multiple needles and the distance between each needle will vary. The denser than the thick one, the effect of the puncture will be different, and the denser will not be easy to penetrate, and it will be shallow. The length at the tip of the needle is the same as the thickness.
