Skin EssentiA kit #4 is the third step moisturizer in the AVST step-up system and contains a high concentration of vitamins A and C. This light moisturizing cream contains a variety of antioxidants, peptides and moisturizers that leaves your skin feeling revitalized and refreshed with a more youthful appearance. Additional vitamin C is added to the moisturizer by including Environ c-boost to your regimen, improving the overall radiance of the skin, and appearance of a more refined tone. It is recommended to use a minimum of 3-4 Skin EssentiA #4 kits before progressing to the Skin EssentiA #5 Kit.