Dead Down Wind ScentPrevent Evolve Scent Control Field Spray uses bio-engineered enzyme technology to prevent odor formation at the molecular level. The ScentPrevent e3 Evolve Field Spray uses Enzyme Scent Prevention (ESP) to break down odor molecules to help you maintain a zero scent environment on the hunt. Evolve Field Spray eliminates a wide spectrum of human odor and contaminant odors like gas and smoke that hunters commonly pick up, helping provide effective scent control for clothing, boots, and gear. Spray bottle can be applied upside down, eliminating application challenges.