Schwarzkopf Natural Styling Classic 1 1000ml utilises the strengthening effect of hydrolysed keratin and the moisturising power of Hydrowave technology to create long-lasting curls and waves which can last upto 12 weeks. Schwarzkopf Natural Styling Classic is available in 3 strengths: 0 (resistant hair), 1 (normal hair) or 2 (tinted or highlighted hair).