Eco-friendly and safe for your cats, the 1.8kg can work up to 30 days and the 7kg silica-gel cat litter can work up to 135 days if maintained properly. The flat crystals, made with sodium silicate sand and processed with oxygen and water, won’t stick to paws and won’t be tracked all over your home. The liquid actually gets trapped inside the crystals, leaving the outer layer of the cat litter dry and releasing a pleasant fragrance. Effective and long-lasting, this premium silica-gel based cat litter gives off very little or no dust. Available in small and large sizes.