Formulated for salon use, the Croda Plex System is a three-step system designed to build bonds and improve hair integrity during the bleaching or colouring process. Step 1 is essential to the bond building system and contains heat-activated ingredients designed to increase hair integrity within the cortex. Step 1 is intended to be added to the bleaching or colouring mixture in a specific ratio to the bleach or colourant (see Measuring and Mixing Instructions below). With heat-activated cross-linking functionality, Crodasone™ Cystine PE is a copolymer of the amino acid cysteine and silane that bonds to hair to impart permanent conditioning benefits. Keravis™ PE penetrates the hair cuticle, building strength from within for optimal strength benefits.