The No.0 Intensive Bond Building Hair Treatment works to visibly strengthen and protect the strands to minimise the appearance of damage. Infused with the highest possible concentration of patented Olapex Bond Building technology, the lightweight formula works as a primer to boost the efficacy of No.3 Hair Perfector. The reparative hair treatment nourishes the hair to encourage a sleek, fuller-looking finish. , , When to Use: Use as a two-part system with No3. , , Application:? Apply to dry hair, saturating from root to ends. Hair should be damp, but not dripping. Leave on for 10 minutes. Do not rinse. Layer No.3 Hair Perfector directly over top of N.0 and leave on for an additional 10 minutes. Rinse thoroughly. , , Routine: Cleanse with Olaplex No.4 Bond Maintenance Shampoo and Olaplex No.5 Bond Maintenance Conditioner.