Keep your furry friend healthy and hydrated with these PetSafe Drinkwell Replacement Carbon Filters. This four-pack of filters is compatible with the PetSafe Drinkwell Original, Platinum, Big Dog, Multi-Tier, Outdoor Dog, Mini, and Zen fountains. The filters help to keep water clean and fresh by removing bad tastes and odors. Each filter features a duo-density polyester pad that catches hair and debris, while the activated carbon helps to remove impurities. These filters are easy to install and should be replaced every 2-4 weeks to ensure optimal performance. Give your pet the clean and fresh water they deserve with these PetSafe Drinkwell Replacement Carbon Filters.