The Kérastase Fusio Dose Booster Anti-Frizz Smoothing and Softening Treatment is designed to enhance the performance of your primary hair mask by targeting specific concerns. This booster focuses on resolving issues related to frizz and lack of softness, delivering concentrated care directly to the hair fiber. When combined with a chosen Kérastase Fusio-Dose base, this additive integrates high-performance ingredients to smooth the cuticle and impart lasting softness. It provides a professional-level solution for managing unruly hair, resulting in a sleek, more manageable finish without weighing the hair down.