Micro-needling is the use of multiple needles that vertically pierce the skin to allow for greater absorption of topically applied skin care products, enhanced stimulation of collagen and elastin growth, and visible improvements in skin tone.Micro-needling opens temporary channels in the most superficial layer of the skin and promotes the bodys natural healing process of producing new skin cells to replace aged or damaged skin. mesotherapy derma pen needles; This cartridge derma pen needle is good for mesotherapy Just replace the needle.Needle length is adjustable to different sizes depend on the areas and purposes of the treatment. Used with derma pen Adjust the length of the microneedle (0.25~3.0mm) Easier to operate in small areas or curved areas High speed in the vertical direction relieves pain and erythema Faster and more efficient than manual microneedles Prevent cross-infection, use disposable needles