This is a zero-fragrance pure moisturizing hyaluronic acid serum. It adopts a multi-hyaluronic acid complex system with large, medium, small and ultra-low molecules to achieve layered hydration: small molecules penetrate the skin for deep hydration, medium molecules fill stratum corneum gaps to soften skin texture, and large molecules form a breathable moisture-locking film on the epidermis to lock in moisture long-lasting and increase skin moisture content from inside out. The formula is streamlined and pure, only retaining core moisturizing and soothing ingredients, alcohol-free, fragrance-free, pigment-free and irritating preservative-free, minimizing sensitization risk. It is suitable for all skin types including dry, oily, combination, sensitive skin and post-procedure skin. It has a clear watery serum texture, spreads smoothly and is non-sticky. It can be used as a daily moisturizing base, layered with other functional serums, or mixed with cream to enhance moisturizing effect. It is recommended to take an appropriate amount and pat gently until absorbed after toner morning and evening, and can be layered in dry seasons to strengthen moisturizing. Long-term use improves dryness and roughness and maintains skin hydration and plumpness.