A firm finishing spray with extra hold for longer-lasting end looks. Nioxin Niospray Strong Hold Hairspray with PROTHICK technology is easy to brush out and helps protect hair density with microbonds, giving a firm but gentle hold to the hair.PROTHICK technology: A professional complex of thickening polymers that wrap around each hair strand and extend, forming bonds between hairs and creating space. Leaves hair thicker-looking and makes fuller styles easier to achieve.