Derma roller contains 192 medical grade Titanium needles, can be applied on any part of your skin. Its application principle is by way of stimulating the dermis layer of collagen and fibroblast proliferation.As a result of micro-needle stimulation, it removes wrinkles and improves skin texture. Micro-needle therapy requires regularly rolling on the skin surface which needs treatment, accompanying with functional nutrition liquid. It can puncture more than 250,000 micro vessels on the epidermal within five minutes. It creates an efficient nutrient delivery system in the epidermis and subcutaneous tissue. End result is beautiful skin!!Whilst pulling the skin taut with your free hand, roll forwards and backwards over the area to be treated. Roll 8-10 times in each direction: vertically, horizontally and diagonally (forwards and back equals two rolls). Apply sufficient pressure for the needles to penetrate the skin to their full length. Lift the derma roller slightly after each roll - this will ensure that the needles create new micro-channels in the skin rather than going over the same ones repeatedly.