Replacement filters for cat drinking fountains. Ensure your cat eats fresh, clean, and healthy food. We help you protect your cat's health. Most filters on the market are made of activated carbon. However, these filters are made of high-quality activated carbon, resin, and cotton. Deeply purified water is safer. Specifications: Name: Cat Drinking Filter. Material: Activated Carbon, Resin. Size: Length: 12.5 cm, Inner Diameter: 3.5 cm, Thickness: 1 cm. Packaging: Package Contents: 6 x Fountain Filters