The Aqua Pure AP810 Whole House Water Filter Cartridges consist of three blue plastic cartridges designed for water purification. Specifically, they are compatible with the Aqua Optima Evolve model, ensuring a reliable and effective filtration system for your home. With the Aqua-Pure brand known for quality and durability, these cartridges are essential for maintaining clean and safe water throughout your household. Easy to install and efficient in removing impurities, these cartridges provide a convenient solution for improving your water quality.