Schwarzkopf Professional BC Bonacure Keratin Smooth Perfect, 750 ml, Hair Masks for Women, The Schwarzkopf Professional BC Bonacure Keratin Smooth Perfect hair mask is an essential step in your hair care ritual. Give it a moment to regenerate and it will repay you with vitality and beauty. Characteristics: regenerates the hair along its entire length makes it easy to comb through and prevents damage goes deep into the hair fibre How to use: Wash with shampoo, then apply to damp hair. Leave to act as instructed on the packaging, then rinse thoroughly.