The Litter Genie Refill Basic system includes a unique five-layer bag that helps contain and eliminate odors. It is constructed to provide six weeks of germ and odor control when utilized for one cat. This Litter Genie for cats refill is designed with a system that tells you when it is time for a new refill.Litter Genie Basic Refill:Refill contains unique 5-layer bag with built-in odor barrier technology to help protect against odors and germsBasic-size refill should last up to 6 weeks with 1 catReady to be replaced when you see a black line on the filmThis cat litter disposal refill is an ideal solution for cat waste odor control