• Compatibility: Filters designed for pet water fountains with a capacity of 2-2.5 liters. Outer ring diameter: 12.7 cm; hole diameter: 3.9 cm. • High-Quality Materials: Made with natural non-woven fabrics, coconut shell activated carbon, and ion exchange resin. • Triple Filtration: The outer cotton layer filters large debris, hair, and dirt, improving water quality by removing residual chlorine, odors, and heavy metal ions. • Easy to Use: Rinse the filter before use to remove carbon dust. Install with the raised side facing up. • Package Contents: 10 cat fountain filters, each individually wrapped. It is recommended to replace every 2-4 weeks to keep the water clean. • Product Dimensions: Width: 13 cm, Height: 1 cm, Length: 13 cm. Total weight: 0.17 kg.