Redken Extreme Length Leave-In Treatment is designed to strengthen damaged hair and support length retention. Infused with the Length Care Complex and Biotin, it helps seal weak strands, reduce breakage, and visibly diminish split ends by up to 78%. Lightweight and easy to apply, this leave-in fortifies fragile hair while promoting stronger, longer growth. When used as part of the full Extreme Length system, it helps reduce breakage by up to 81%, making it an essential step for maintaining healthy, resilient hair.