The Nº.4 Bond Maintenance Shampoo, infused with patented OLAPLEX Bond Building Technology, is a highly concentrated reparative shampoo that hydrates and nourishes hair. - The Nº.4 Bond Maintenance Shampoo improves manageability and softness - The Nº.4 Bond Maintenance Shampoo increases shine and leaves hair looking healthier - The Nº.4 Bond Maintenance Shampoo helps prevent breakage and split ends New & unopened. Bundle with OLAPLEX No 0, No 3 and No 5 in my closet.