Redken’s Acidic Bonding Concentrate System is their most concentrated all-in-one formula for strength repair for all types of damaged hair. This sulfate-free system provides ultimate strength repair, intense conditioning and color fade protection. Featuring Citric Acid, this system contains a concentrated bonding care complex that reinforces weakened bonds within your hair to improve hair strength and resiliency. It repairs strength in damaged hair strands, provides heat protection up to 450 degrees, tames frizz, adds shine and reduces hair breakage. This pH-balancing system is specifically formulated with an acidic pH to defend against the negative effect of hair coloring, styling tools, and even water, which has a pH of 7, to balance hair’s pH back into a healthy range of 4.5-5.5. The result? Healthier looking and feeling hair.