TRESemmé Thermo Sculpt Memory Priming Hair Serum provides up to 72h style retention*. Powered by Salon Grade Thermo-Activated KeraKinetic Tech, it's the final step in a hair care system that transforms the way hair responds to heat. Activated by heat-styling, crystal-like molecules re-form in the core of the hair, enhancing resilience and the ability to retain style. Apply 1-2 pumps of serum to damp hair, focusing on mid-lengths to ends, and style. For best results, complement your routine with TRESemmé Thermo Sculpt Memory Shampoo, Conditioner and Hair Treatment Mask.