Schwarzkopf OSiS Hold Session Extra Strong Hold Hairspray 100ml. Allowing you to maintain long-lasting styles without compromise, OSiS Session is an extra strong hold hairspray that keeps your hairstyle in place even under demanding conditions. It ensures your look stays exactly as it should be, remaining cool even in windy or rainy weather. Apply to dry hair to maintain your look. Let your style speak for itself with OSIS+ hold! This product comes in a large spray can, providing a generous amount for numerous styles. The can itself is predominantly white with the product name OSIS+ printed in red letters.