About the Product Sunsilks new Perfect Straight Shampoo uses the breakthrough Straight-Lock Technology to give you silky, smooth, and straight hair. The special molecules present in it have an advanced formula that penetrate deep into your hair fibers to reduce frizz and help straighten hair strands. The shampoo controls each wet hair strand and aligns them evenly as your hair dries. Get beautiful, straight hair every day with this Perfect Straight shampoo from Sunsilk. Co-created with Sunsilk expert Yuko Yamashita, Sunsilk Perfect Straight Shampoo is the ideal shampoo to get straight, luscious, tangle-free hair. This is a 340 ml good-sized bottle that will last you long.