Powerful and useful cartridge filter set keeps your PureSpa Jet Massage water clear and fresh, making for a more relaxing spa experience; Quantity: 8 Maintains and cleans easily with heavy-duty Dacron paper, providing the ultimate filtration for your hot tub; Diameter: 4.25 inches For maximum efficiency, clean cartridges each week and replace them once per month or sooner Designed for keeping your hot tub and sap safe and clean, working hard to increase the performance of your pool Works with all Intex PureSpa models including 28403E, 28407E, 28443E, 28453E, 28421E, 28423E, 28413E, and 28453E Keep your spa water clean for longer periods of time with the PureSpa Type S1 Easy Set Spa Filter Replacement Cartridges from Intex. These authentic replacement cartridges are made specifically for your Intex PureSpa. Compatible with all Intex PureSpa models like 28403E, 28407E, 28443E, 28453E, 28421E, 28423E, 28413E, and 28453E, these filters will be able to do it all. Replace your filter cartridges regularly for the best results. Recommended that you replace your cartridges every 2 weeks, these filters will enhance your spa performance. The heavy-duty Dacron paper construction provides the ultimate filtration process. Whether you're relaxing after a long day or enjoying your hot tub with friends, these filter cartridges ensure the cleanest and safest water for all your guests to enjoy. With 8 replacement cartridges included, you'll always have a filter cartridge close at hand. Ensure the longevity of your Intex PureSpa by using the PureSpa Type S1 Easy Set Spa Filter Replacement Cartridges from Intex.