Get beautiful, sleek hair that lasts all day with this waterless serum. Goldwell Style Sign Sleek Perfection Thermal Spray Serum speeds up the straightening process, & with added humidity protection, you'll relish in hassle free, silky straight hair. This serum is an absolute essential for anyone who wants to enjoy sleek, smooth & shiny locks. This easy to use spray can be used straight onto dry hair before straightening. This Goldwell product has no hold factor. To Use: Spray onto dry hair before using a straightening tool.