Internal aquarium filter:
The filter is supplied with 2 sponges.
It absorbs the waste and filters the water in the aquarium

Only fits for 6Watt500L / h 15watt1000l/H 4-in-1 Internal Aquarium Filter
Biochemical-sponge can effectively filter waste and improve the circulation system to maintain a clean water environment.
Replace or clean filter sponge every two weeks or sooner for optimal performance.
Easy to seperate and clean,absorbs odors and discoloration,provide a healthy water for your aquarium
Included 4Pcs Biochemical-sponge only