With its pH of 4.0, the Colour Lock is the first step towards long lasting colour! Use this professional formula after any colour service to smooth and tightens the cuticle, effectively locking in colour.VEGAN, PARABEN FREE, GLUTEN FREE, SULFATE FREE, NO ARTIFICIAL COLOURS, COLOUR SAFEUSE: Apply after any chemical service. Distribute thoroughly. Indulge for 5 minutes. Rinse.