The DUO SET THE NIACINAMIDE 15 Serum by COSRX is a skin care set specifically designed for all skin types, featuring hyaluronic acid as its active ingredient. This set includes two 30ml serums, perfect for the face, and is formulated with an SPF of 30 for added protection. The products are cruelty-free and have a period after opening of 12 months, making them a reliable choice for skincare enthusiasts looking to pamper their skin with high-quality ingredients.