A weightless and invisible leave-in treatment that protects hair against heat and the mechanical damage associated with using heated tools. Distributes easily into hair while providing extreme heat protection up to 232˚C / 450˚F. Apply to damp hair after you wash & rinse.From science, Copolymers aid in selectively binding to regions of the hair that are damaged, to protect and improve, while Polyquaternium smooth over the surface of the hair, provide a layer of conditioning, and a weightless protective shield.