Filter cartridges keep the water clean. They are easy to install and maintain. They just require regular rinsing under the tap. However, if they remain dirty or discolored after rinsing, they must be replaced. Otherwise, the filter pump may be damaged. MSPA filters are not made of paper, but of polypropylene: a guarantee of quality and longevity. Supplied with 90 pleats and 2 filter cartridges - a genuine pair of quality replacement filter cartridges. Upper for Mspa spas Diameter: 10.6 cm x 6.7 cm (4.2" x 2.6") Fits MSPA spa brand models only - for Tuscany, for Camaro, for ALPINE, for Silver Cloud, for Tekapo, for Mono, for Reve, for Bliss, for Baikal, for Lite, for Nest, for Starry, for Aurora