This heat protection spray is used when heat is applied to a persons hair (ie. Flat iron). It's applied to damp hair before blow drying or curling/straightening. It has an adjustable nozzle to control the flow of the spray...which really works well when you want to get an even amount over your hair. It holds the shape/curls/ other styles well, my hair didn't start to flatten til at least 1/2 way through the day (my hair is very unmanageable). Usually my styles last only an hour. When you combine this product with other body volumizing products...it performs very well.