Dyson Chitosan Post-style serum travel mini is a lightweight post-styling hair serum that provides flexible, all day hold for smooth, shiny, frizz-free hair. Formulated for all hair types, this lightweight serum simultaneously nourishes individual hairs, while locking their shapes with a flexible bond structure without compromising your hair s natural feel. For use on dry and styled hair to define style. Travel-friendly format is easy to use, perfect for on-the-go styling.