Una An instant dose of hydration and intense nourishment is provided by the Bumble and bumble leave-in treatment. Prep Primer. Provides your hair with everything it needs after washing, without having to go through multiple tempo of the necessary in the bathroom. It will help you straighten your hair by restoring its naturale shine and integrity of their struttura. It promotes their regeneration and helps make combing easier. All this in modo Simple, quick, and rinse-free. Just apply, wash, or comb through to care for the beauty and health of your hair. Try this leave-in treatment and discover a modo simple and quick to regenerate with many other benefits.