Oase Biosmart Gravity Pond FilterProduct Details UPC 706759569293 Manufacturer Part No 56929 Bullet1 Biological filtration stage water is channeled through a series of foam filters that allow settling of beneficial bacteria Bullet2 Multi stage mechanical and biological filtration system in a compact package Key Features Biological filtration stage water is channeled through a series of foam filters that allow settling of beneficial bacteria Description Biosmart Filter 5000 1