WHAT IT IS OSiS Session Label Strong Hold Hairspray is an ultra-fine mist with uncompromising control. WHAT IT DOES The innovative micro-diffuser spray technology delivers an ultra-fine strong holding mist to the hair for long-lasting style protection that rsquo s a cinch to brush out. Schwarzkopf Professional OSiS Session Label Strong Hold Hairspray helps hair retain a natural clean feel along with strong style hold. 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.