PETSTANDARD Replacement Filter Compatible with Whisker City® Water Fountain.
Filter Measurements: 5.0" x 2.5" x 0.25".
To prevent the activated carbon dust from shedding into water, please soak the filter in water for 10 minutes then rinse thoroughly under running water before using.
Replace the filter every 1 to 2 weeks in summer and 2 to 4 weeks in winter. If multiple cats are using the fountain, more frequent replacement will be necessary.