Hair is up to 10 times more sensitive to damage when it is wet. When exposed to heat the hair needs protection against heat and mechanical damage during the blow-dry. System Professional Repair Perfect Hair provides hair with volume and improves its structure. The leave-in foam deeply strengthens the hair fiber. Hydrolized keratin and amino acids penetrate the porous zones of the hair structure and restructure the damaged area. The protective polymers of the Thermo-Resist formula make the hair more resistant against the effects of heat for strong and resilient hair.