With indicator crystals. 100% natural. Reduced tracking. 1 month supply! Complete Odour Control: The millions of micro-pores in each silica granule act like sponges, ensuring odour control that is fast and complete. Our exclusive Indicator Crystals fade in colour as litter is used, letting you know when it's time to replace. Environmentally Friendly: For disposal, empty entire contents of litter box into trash receptacle. Produced and packaged in China.