BOND RX 2-Step Professional System. Turn any lightening or hair colour service into a bond-building treatment. The Paul Mitchell® Bond Rx 2-Step Professional System is a treatment to strengthen and condition fragile hair. Step 1 Professional Bond Builder - Includes measuring unit dispenser Step 2 Professional Bond-Building Sealant The BOND RX 2-Step Professional System forms a consistent, protective barrier from root to tip to restore strength and resilience to fragile hair.* Reduces exposure during lightening and permanent hair color services without altering the formula. Restores lipids within the hair to strengthen and replenish strands. *Using Step 1 and Step 2, as compared to virgin hair. Results based on third-party clinical testing. This kit includes: Bond Rx Step 1 Professional Bond Builder, 250ml Bond Rx Step 2 Professional Bond-Building Sealant, 500ml Measuring unit dispenser x1