K18 leave-in molecular repair hair maskA leave in treatment mask for all hair types that clinically reverses damage in 4 minutes. The patented peptide technology works to repair damage from bleach, color, chemical services & heat restoring strength, softness, smoothness, and bounce to hair. how to use IN the shower Shampoo, do not condition. OUT of the shower Towel dry thoroughly. Begin with 1 pump of the K18 Mask and add more as needed depending on the length, thickness, and condition.