The Olaplex No.4 Shampoo and No.5 Conditioner are part of the Olaplex Bond Maintenance? system, designed to repair, strengthen, and moisturize all hair types. Here's what each product does: Olaplex No.4 Bond Maintenance Shampoo: This shampoo cleanses the hair while maintaining the bonds that were repaired and strengthened by Olaplex treatments. It helps to restore internal strength and moisture levels to the hair, leaving it feeling soft, smooth, and healthy. Olaplex No.5 Bond Maintenance Conditioner: The conditioner helps to detangle, hydrate, and protect the hair, reducing frizz and flyaways. It nourishes and strengthens the hair, leaving it more manageable and resilient to damage. The "bonus treatment" could refer to a variety of Olaplex products, as they offer various treatments and stylers. It's essential to clarify what the bonus treatment entails, as it could be anything from the No.3 Hair Perfector, a leave-in treatment, to one of their other products like a hair mask or styling product. Each of these treatments serves a specific purpose, from repairing and protecting the hair to providing additional moisture and shine.