Derma Roller for hair growth. 192 titanium micro needles, 0.5mm depth to reach epidermis layer under scalp without bleeding. Derma Roller causes low-level trauma to the scalp epidermis layer which will encourage the wound healing process creating new tissues. Also, it stimulates the scalp's natural anti-aging agents as well as increasing blood circulation to the follicles. It creates a pathway for Odjibik Root Activator Serum so that active ingredients can penetrate into the roots.