Naturally Fresh Mullite-Cat Clumping Litter is an eco-friendly, clumping litter made from all-natural walnut shells. Walnut shells have the unique ability to control ammonia odors, meaning Naturally Fresh neutralizes odors organically without relying on harsh perfumes. Naturally Fresh is sustainable, non-toxic, and free of harmful silica dust. All Natural & Biodegradable Virtually Dust-Free and Low Tracking Proprietary Natural Malodor Counteractant Controls Urine and Fecal Odors Homegrown in the USA Clay Free, Corn Free, Grain Free For Households managing litter boxes with multiple cats.