K18 leave in molecular repair hair mask 50mlK18 leave in molecular repair hair mask 50ml 4 minute leave in treatment to reverse damaged hair like new. This leave in mask heals and strengthens hair with lightweight moisturizing benefits to detangle and keep hair smooth and soft, without weighing it down. For best results, use for the first 4 6 consecutive washes following a service, and then every 3 4 washes as needed to maintain hair strength. Shampoo, do not condition. Towel dry thoroughly.