1. red light (wavelenght: 628 nm) The red light which can penetrate 8 ~ 10 mm apply to all skin types. It can reach to the dermis layer to stimulate fiber cells, improve blood circulation and collagen synthesis, activate and smooth skin, reduce wrinkle. blue light (wavelenght: 465 nm) The blue light which penerate about 0.5 mm of skin is helpful to soothe skin, against acne & rashes. It's suitable for oily and acne skin. It can regulate the sebum secretion, so it helps to eliminate the acnes and comedones, and it can shrink pores and tighten skin as well. of green light (wavelenght: 520 nm) It can relax skin and relieve the pain of skin. Suitable for the mixed skin type. Feature 1. 3 MHz ultrasound vibrates 3 million times per second, tightening skin and improving the absorptive capacity of skin. 2. Ion+: clean skin thoroughly: Ion-: nourish skin deeply. 3. Red, blue & green photon for rejuvenate skin. 4. Vibrating massage improves blood circulation & slims skin. 5. Grooved collar for binding cotton pad for help cleaning.