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 sold in a 2-Pack and are compatible with the Drinkwell® Lotus, Avalon, Pagoda and Stainless Steel 360 Fountains. Key Features :•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 •Compatible with Drinkwell® Stainless Steel 360, Lotus, Avalon, and Pagoda Fountains.