Keep your pool water clean and clear with a Bestway Filter Cartridge (Type I). This replacement cartridge is designed for filter pumps with a 330 gal. (1,249 L) per hour flow rate and measures 3 in. x 3.5 in. (8 cm x 9 cm). These filters do the dirty work for you, sifting out the dirt, oils and micro-debris from your pool to keep it looking and feeling its cleanest. Clean the filter as needed with a garden hose or simply replace your filter every 2 weeks for best results, and you will be on your way to enjoying every moment in your fresh, relaxing pool while extending the lifespan of your pool and pump. Stock up and always have a few on-hand so you never run out!