1.540 Needles Derma roller 2.Have sterilized 3.Use seal package 4.Use Disk Needles 5.for face slimming 540 Needles Derma Roller for face slimming1.What's a Derma roller?Derma rollers have become increasingly popular over the last decade, and many women and men use them for all sorts of skin-related problems: acne, scars, cellulite, stretch marks, anti-aging, wrinkles, and even hyper-pigmentation. ...