PRO THICK Technology is a complex of thickening polymers that form bonds between strands for space. The space created gives a thicker appearance on the hair & makes achieving your desired style easier. Nioxin Pro-Thick Niospray Strong Hold provides extra hold that helps to create a fuller-looking effect*. This firm finishing spray will set your style in place & is easy to brush out. How to use: For use on dry hair. Style hair & use spray to set style.