This Hydronix Bc-45-2001 NSF carbon block filter is the perfect addition to your water purification system. Designed to work with Aqua Optima Evolve models, this filter uses carbon block filtration method to provide you with clean and fresh-tasting water. With its white color and compact design, it is easy to install and use. The filter comes in a pack of one, making it a great choice for those who want to improve their water quality.