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 be aware that there are many incorrectly shaped versions of these filters available at similar prices, such as square or hexagonal designs. These shapes result from low-quality manufacturing and do not fit as well as round filters, which provide a more consistent surface area. Some are also excessively thick, which can restrict water flow and place unnecessary strain on your pump. The original filters I used lasted approximately one week and were difficult to clean. After extensive testing, I developed the filters offered in this listing. I have been using them successfully with no issues. These filters are more afable than original models, allow better water flow, and provide improved filtration performance. I have sourced round filters instead of the lower-quality, misshapen alternatives commonly available. Round filters offer superior fit and more consistent filtration due to their uniform surface area. These filters require regular maintenance. Bromine is recommended as it is odorless, gentle on skin, and compatible with foam filtration systems. If using chlorine, it is strongly advised to replace the filters weekly. Note: These filters may experience slight color fading with normal use. This is expected and does not affect performance. Some sellers dye their foam green to mask discoloration, but I prioritize transparency with customers.