The Olaplex No. 9 Bond Protector Nourishing Hair Serum is a lightweight, leave-in serum designed to protect and nourish your hair. It offers several benefits: Heat Protection: Shields hair from heat damage up to 450°F (232°C)1. Pollution Protection: Guards against daily environmental damage for up to 48 hours2. Nourishment and Shine: Provides hydration and enhances shine, leaving hair smoother and frizz-free3. This serum features Olaplex’s Bond Building Technology™, which helps to strengthen and repair hair1. It’s a versatile addition to your hair care routine, especially if you’re looking to maintain healthy, shiny hair.