The foam filters which come with every cat fountain protects the pump from cat hair & debris, reducing the frequency of taking apart the pump for cleaning. Each filter lasts at least a year to two years, depending on usage and care. You can learn more about them here.
The optional carbon filters remove impurities in your water such as chlorine and odors. The fountains for some cats will need this, for others not. Each pack of two will last from 6 months to a year. ou can learn more about them here.
SHIPPING is included in the price. Filters purchased without a fountain will ship via USPS.