*Never opened* The Nº.0 Intensive Bond Building Hair Treatment, infused with patented OLAPLEX Bond Building technology is an intense treatment that boosts the efficacy of OLAPLEX Nº.3 Hair Perfector® for deeper repair while strengthening and protecting the integrity of the hair. - Boosts the efficacy of OLAPLEX Nº.3 Hair Perfector®. - Absorbs quickly to jumpstart repair deep within the hair strand. - Strengthens and rebuilds hair bonds. - Scientifically proven: 68% more repair & 3x stronger hair.