5F needles serve for perfect, precise coloring, tender feathering, and even making contour lines when working with a needle edge. Used when creating short strokes and lines (depending on whether the master uses their flat or rib position or raises the needles) they make even shading. These flats are perfect for alternating colors in tattoos and transferring halftones. This stuff is also used for making dense color. Also, these needles injure the skin less than other type of similar stuff. 5F needles diameter is 0.35 mm. The diameter of the needle base is 0.40 mm. The length of needles with base is 50 mm.