Red light wavelengths measure between 630-700 nm. These are an ideal length to penetrate skin cells and sebaceous glands, offering benefits for skin texture and tone, smoothing fine wrinkles, promoting collagen production and generally rejuvenating the appearance of skin. Many people who are focused on red light benefits specifically for skin, such as increased collagen production, acne healing or scar and stretch mark fading, select the ‘red only’ configuration.