Redken Extreme Length Primer Rinse Out Treatment Size: 30ml Brand New Description Extreme Length Primer Rinse Out Treatment: A rinse out biotin enhanced split-end primer treatment that builds strength from root to tip, helping you achieve your maximum hair length. Formulated with biotin Provides weightless conditioning Builds strength from root to tip How to use Apply on damp hair from root to ends after shampooing with Extreme Shampoo. Leave on 2-5 minutes. Rinse thoroughly. For best results, follow with Extreme Length Sealer.