If you have a PETKIT water fountain, these Filter Units 3.0 are essential for keeping your pet's water clean and fresh. This 5-pack gives you a good supply so you're always prepared when it's time for a filter change. These upgraded filters work with several PETKIT models including Eversweet 2S, Eversweet 3, Eversweet 3 Pro, Eversweet Solo, Solo 2, Solo SE, and CYBERTAIL fountains. The multi-layer filtration system is really effective - it uses double filter components and a high-density micropore filter to remove pet hair and other impurities from the water. What's important to remember is to soak each new filter in clean water for at least 10 minutes before first use - this primes the filter and ensures it works properly. PETKIT recommends replacing the filters every 30 days under normal use, but your fountain's LED indicator will actually remind you when it's time for a change. After replacing the filter, don't forget to reset your device so it can properly track the new filter's lifespan. The quality is genuine PETKIT, so you know they're made with the right materials rather than cheaper alternatives that might cut corners. Combined with weekly fountain cleaning and water changes, these filters help maintain optimal water quality and protect your fountain's pump from damage. Your pets will appreciate having clean, fresh-tasting water always available.