Aqua Ultraviolet Ultra Bio Media is a filtration media with a very high bio film surface that offers superior bacterial adhesion and colonization. Excellent flow through within the media Patented ""Y"" shaped media Aqua Ultraviolet Ultra Pond Filter Material is the premier choice for biological filtration Lightweight tubular bio-media Very high surface areaAvailable:A70012 -One cubic foot (8.5lbs.)A70011B - Twenty-seven cubic feet (225lbs.) A70012 - One cubic foot (8.5lbs.)