CHITOSAN POST STYLER SERUM 3.4OZ. Benefits: Holds and hydrates your end style, for instant definition. Nourishes the hair surface, for smoothness up to 24 hours.**. Flexible, all day hold*. Up to 50% less frizz*. Shields styles from up to 80% relative humidity. Features: Dyson Triodetic technology: Flexibly locks in styles for long-lasting hold with a lightweight natural feel. Precision pump: Engineered to dispense an exact amount of product every time, for controlled usage. Lightweight serum for even application to smooth, define, and enhance styles. Amino acids: Repair signs of surface damage. Hyaluronic acid: Helps reduce frizz caused by humidity, for softness and shine. Chitosan: Derived from oyster mushrooms and uses a lightweight structure of bonds that allows each strand to move, flex, and recall its style, in unison with the rest. 4-5 oyster mushrooms used in every bottle. Fragrance: Dyson signature fragrance. A unique and subtle blend of green and floral notes sparkling bergamot, subtle florals, warming cedarwood, moss and musk. All Dyson full-size formulation products are refillable. Order a refill and follow instructions on the cartridge to replace. *vs. untreated. **vs. untreated hair. Tested at relative 80% humidity. :