K18 Professional Molecular Repair Hair Mask is used after the service to repair damage caused during a chemical salon service. Its pH of 5.0 - 6.0 helps to close the cuticle. In addition, it introduces valuable conditioning agents, leaving hair soft and supple.This silicone-free formula penetrates deep into the hair cortex and restores the hair's natural, youthful condition in just 4 minutes It also soothes the hair cuticle and porosity.Application: 1.Shampoo with a shampoo of your choice, rinse, and do not use conditioner. Dry thoroughly with a towel.2. then apply the Pofessional Molecular Repair Hair Mask.3. leave the mask on for 4 minutes, without rinsing (even when shampooing)When styling - After 4 minutes, apply styling product if desired, then dry/style....When cutting - Begin immediately.When matting down - Apply toner to mask after step 3.Repeat steps 1-3 after toning is complete.PROFESSIONAL TIP: Applying the mask before toning evens out the porosity of the hair and helps the