When you wash your hair, shampoo opens the surface structure of the hair – the cuticle. That's why it's important to add hair care after washing to close the cuticle. This is exactly what conditioner will do. Bumble and bumble Thickening Volume Conditioner. In addition to closing the hair fibers, it provides them with nourishment, hydration and softening, which beautiful, shiny and healthy hair cannot do without. It protects them from mechanical damage and dryness, and also smoothes the surface helping to soften them and making combing and subsequent treatments easier.