WHAT IT IS OSiS Session Label Dust It Flex is infused with Lava Rock and Silica providing flexible volume and mattifying roughness. WHAT IT DOES Schwarzkopf Professional OSiS Session Label Dust It Flex adds flexible volume to roots as well as long-lasting and strong texture for mid-lengths and ends. This powder is naturally rough and matte easy to wash out and is suitable for dark and light hair colors. OSiS Session Label brings session styling performance and premium styling precision into your hands for unlimited hair reinvention. High performing super-dry hair sprays as well as weightless shine and mattifying products guarantee highly precise hair shaping amp forming - as seen on the latest runways.