Prokure D Deodorizer Extended Use (50 grams - 4000 cu ft) ProKure D releases chlorine dioxide gas which neutralizes all odors associated with growing plants in an indoor (contained and unoccupied) environment. No hazardous residues left behind! Prokure D Deodorizer Extended Use Gas Pouches generate small amounts of gas with exposure to humidity in the air for up to 30 days. Perfect for controlling odor inside and outside of agricultural facilities by use near exhaust vents, doors, windows and other openings. ProKure D Extended Use pouches release a safe, low level of odor-eliminating gas, that upon consistent contact with ambient humidity, destroys the source of the odor