Catit Magic Blue Air Purifier for Litter Boxes Magic Blue absorbs and retains up to 80% of ammonia and reduces fecal odors by an average of 40%, depending on your cat's diet Contains reusable cartridge and 2 pads (one month) Safe and easy, non-toxic and unscented Magic Blue absorbs hazardous ammonia gases 25 times more effectively than carbon-based filters! Use Cat it Magic Blue for better air quality for you and your cat!