• Cat fountain filter compatible with GOOSTOO fountain. • Filter size: 8.5*4*1.5 cm. • Effective filtration with layers of cotton, coconut shell activated carbon, and cation exchange resin. • Filters fine impurities, hair, heavy metals, and removes unpleasant odors from the water. • Improves water quality and keeps it clean. • Includes 6 blue filters and 6 sponge filters in a unified paper box. • Carbon filters protected by a plastic layer to prevent damage during transport. • Provides clean and fresh water to your pet, reducing the risk of urinary tract infections. • We recommend changing the filter every 2-4 weeks for a better drinking experience. • Before use, soak the filter for 5 minutes to remove carbon dust.