60 days. 240 clumps (Based upon laboratory testing of synthetic cat urine absorbency on the average daily litter box usage of one cat). Highly absorbent. Up to 50% lighter than traditional clay scoop brands (Based upon laboratory testing, as compared to traditional clay scoop litter. Results may vary based upon individual litter changing habits). This product is filled by weight, settlement will occur. Perfume and dye free. Quality & trust guarantee. Quality guaranteed or your money back. For product questions or concerns, contact us at 1-877-846-9949.