Size: 1 Pack Dr. Elsey's Ultra Litter Additive contains a scent that naturally attracts cats and kittens to use the litter box. Non-use of the litter box is the number one behavioral reason cats are abandoned, abused, and placed in shelters. Designed for cats that are not using their litter boxes. Dr. Elsey's Ultra litter Attractant is the only litter attractant to provide a clinically tested and consumer proven solution.