The Drinkwell® Replacement Foam Pre-Filters trap any large debris and hair in the water, before they reach the pump, providing cleaner water to your pet. These foam filters help keep the pump cleaner in between cleanings and maintain the fountain's flow rate. These filters are compatible with the Drinkwell® Avalon, Pagoda, Stainless Multi-Pet, 1.8 Litre, 3.7 Litre, and 7.5 Litre Pet Fountains. 2-pack of filters Filters keep your pet's water clean and fresh! Improves filtration Capture debris and large particles Keeps pump cleaner Replace foam filter every 4 to 6 weeks Compatibility Compatible with Drinkwell® 1.8 Litre, 3.7 Litre, 7.5 Litre, 360 Stainless Steel, Avalon and Pagoda Pet Fountains.