Natures Miracle Advanced Stain & Odor Gal (Pack of 4) Pack of 4 (4 gallons total) The most advanced Natures Miracle formula, incorporating the best performing cleaning technologies Deeply cleans to remove all pet mess traces, discouraging the spread of unsanitary pet waste Pet-Block System removes pet pheromones and destroys odors on contact to prevent re-soiling Faster drying to minimize tracking