This Type I Filter Cartridge 2-Pack will keep your pool consistently clean, clear and safe for better visibility. Its ultra-fine, heavy-duty filter paper ensures that dirt and debris do not get recirculated into the pool. Every cartridge needs to be replaced only every 2 weeks, keeping your water clean without hassle. The Type I cartridges are compatible with the Funsicle RX330 Cartridge Filter Pump. Available in a convenient 2-pack, you will get maximum value with an entire month's worth of filter cartridges, so you can enjoy a refreshing summer.