General description 100% brand new and high quality, this reusable foam filter cartridge is designed for Bubble and Jetted Pure spas, specifically as a replacement for the S1 carton. Replacing the filter elements of paper filters is essential for daily pool maintenance, and using cleaning and reusable foam filters can significantly reduce your costs over time. Although the initial cost of the cartridge is slightly higher than that of traditional cartridges, its longer lifespan makes it a cost-effective choice. Technical specifications Size: 10.8 x 7.3 cm Center hole diameter: approximately 4 cm Material: sponge Package Contents: 64 x Filter Sponges Measurement allowed error: +/- 1-3 cm Other information It takes 2 hours for the compressed product to recover its color: blue Note: Light reflection and different displays may cause the color of the item to differ slightly from the actual product.