K18 HeatBounce Leave-In Conditioner and Heat Protectant is powered by advanced Resilicore heat-shielding technology to defend hair from the inside out. It protects against heat damage up to 450°F, while conditioning, detangling, and shielding hair from mechanical stress, UV exposure, and environmental factors that contribute to color fading, dryness, and breakage. Inspired by resilin—a natural protein known for its heat resistance—Resilicore is a cutting-edge innovation that goes beyond surface protection. Unlike traditional protectants that sit on the cuticle, Resilicore penetrates deep into the cortex, where heat damage begins, forming a powerful internal shield. Suitable for all hair types and textures, including extensions.