WetBlock HD is a high-performing, water-repellent spray that keeps any surface dry. Using super hydrophobic, nano-technology which top research scientists developed for the US Military, WetBlock HD literally blocks the wet away; you can see water rolling off any surface. I It's very easy to use. Spray WetBlock HD on the surface you protected, let it dry and you'll have the confidence that it will repel anything that's wet. Use it indoors and outdoors with just one simple spray, you'll be able to keep what you want dry. WetBlock HD is always on the job!