Kérastase Chronologiste Thermique 150mlKrastase Chronologiste Regenerating Leave In Treatment 150ml is a smoothing leave in treatment that refines hair texture, prevents frizz for 24 hours, and protects the hair against heat up to 230 degrees Celsius. This leave in conditioner seals the cuticle against humidity, making your hair look fabulous. It helps with styling and gives you a smoother, more refined look when blow drying with a bit of this in your hair.