Create customizable straightness for up to 30 shampoos. Concen-Straight Smoothing Treatment is a gentle yet potent, single use straightener. Formulated with Concen-straight Technology™ (patent-pending), which helps maintain hairs natural integrity, create smoothness, manageability, shine and styling ease; frizz and flyaway reduction. Heat gently unlocks the treatments artistic potential: Flat irons render hair pin-straight, blow dryers create body and movement while air drying reveals natural, more manageable texture. Formaldehyde free. Cysteine free. Lye free. Appropriate for all hair types, colors and textures. Best for the curly, thick, coarse, frizzy, unmanageable, unruly (or any combination thereof).