A bond building; reparative hair oil serum.Build your bonds back together with the Bumble and Bumble BondBuilding Repair Oil Serum. This reparative hair oil serum builds bonds and strengthens hair back from breakage and damage caused by bleaching; colouring; and heat styling whilst also helping prevent future damage to ensure your hair stays salon fresh in between hairdresser appointments. Stronger; happier; healthier hair!