Replacement filters compatible with the Vekonn 2.5L stainless steel top elliptical cat fountain. 6-pack replacement filters, including 4 carbon filters and 2 sponge filters. Carbon filters: 4.9" x 4.9" x 1.4" measurements. Sponge filters: 2.56" x 1.18" x 1.18" measurements. The replaceable charcoal filter removes dirt and food particles, while the sponge filter effectively prevents pump blockage. Please soak and rinse the filter with water thoroughly before being used. It is recommended to replace the carbon filter every 2-4 weeks and the sponge filter every 2-3 months. Vekonn Cat Water Fountain Filter, 6 Filters Pack for Stainless Steel Top Elliptical Pet Fountain