4 in 1 derma roller is a scientific and comprehensive device with 3 separated heads of different needle count, significantly, there is a dedicated disinfecting tank. DRS Derma Rollers are made of many high grade micro needles which roll over and penetrate the skins upper surface painlessly. These revolutionary devices provide two major benefits. Stimulating collagen growth which significantly improves the appearance of scars, fine liness, wrinkles, stretch mark, and acne scars. Allowing the transdermal application of creams, gels and oils, to be absorbed far more effectively massively. This is relevant to hair loss treatments and cellulite reduction.