Get the most out of your cat litter with Ultra Micro Crystals Cat Litter. Made with sand-like silica gel crystals, which are a naturally occurring mineral made of water, sand, and oxygen, it offers superior moisture and odor-trapping qualities. In fact, it absorbs urine instantly and leaves litter dry to the touch, which in turn provides maximum odor control. And since the moisture then evaporates, the crystals can be raked and used over and over again for up to a month, making this an earth-friendly options as well. Totally non-toxic and safe for cats, it is soft on the paws and cuts down on tracking.