Keep your furry friend's water clean and fresh with this complete 20-pack filter set! You get 10 filters PLUS 10 foam filters - everything you need to maintain your EVERSWEET Solo SE/2S/3/3Pro or CYBERTAIL 63oz pet water fountain. These aren't just any filters - they feature a serious three-layer filtration system with activated carbon and non-woven fabric that actually works to remove pet hair, food bits, nasty microorganisms, and those unpleasant odors from the water. Here's a pro tip: always rinse the filter under running water for 3-5 minutes before popping it into your fountain. During summer months, you'll want to swap these out every 1-2 weeks, and in winter, every 2-4 weeks should do the trick. Got multiple cats? You'll probably need to change them more often since they'll be working overtime. Each filter measures about 5.5 inches across with a 0.5-inch hollow circle and 0.4-inch thickness - perfect fit for your fountain. Your pets will thank you for the cleaner, healthier water!