100% New And High Quality Color: Blue Qty: 4 pcs You are looking at Z type foam filters that are compatible with many models of inflatable hot tubs. Please note, there are many differently shaped versions of these filters available, such as square or hexagonal. These shapes are often the result of lower manufacturing standards and do not fit as effectively as round filters, which provide a more consistent surface area for filtration. Some of these alternative shapes are also unusually thick, which may restrict water flow and place unnecessary strain on your pump. A round filter is better suited for housings designed for that shape. The original filters were used for approximately 12 months and were found to last only about a week, with difficulty in cleaning and high replacement costs. After extensive testing, these foam filters were selected for improved performance. They have been in use with no issues. These filters are more affordable than original filters, allow better water flow, and provide effective filtration. Round filters have been sourced instead of irregularly shaped alternatives, ensuring a better fit and improved performance due to consistent surface area. These filters require regular maintenance. The use of Bromine is recommended, as it is odorless, gentle on skin, and compatible with foam filtration. If using Chlorine, weekly filter changes are advised. Please note that some color loss may occur with normal use. This is expected and not a defect. Some sellers dye their foam green to mask discoloration, but transparency is prioritized.