... Long Time Usage Various Color and Fragrance SILICA GEL CAT SANDCat sands can absorb all excrement and urine ... and sanitary environment. At the same time, cat sands can be used as an air-fresh agent, which absorbs ... room fresh and clean for us all. Because cat sands have their unique performance, that is only ... cats, 15days; three cats, about 10 days.4.Cat sands saturated by the pet feces must be moved ...