Seeing dull hair, tangles, or poor style retention? These could be signs of pollution or heat damage. Protect your hair from daily damage with this weightless, leave-in, silicone-free Olaplex N°. 9 Bond Protector Nourishing Hair Serum to shield hair from pollution for 48 hours and provide heat protection up to 450°F (232°C). With antioxidant-rich Red Algae Extract and scientifically proven OLAPLEX® Bond Building Technology™.