What makes healthy hair dull, discolored, dry, unmanageable, or oily? Buildup. Nº.4C Bond Maintenance® Clarifying Shampoo is new technology to reveal your healthiest hair. Optimize your hair repair results by removing more impurities that damage hair. Harsh clarifiers can leave hair like straw. Nº.4C is sulfate-free & pH balanced to maintain hydrated hair.