Fluval Aquarium Filter Foam Block 2" length x 3.1" width x 7.5"

The Fluval Aquarium Filter Foam Block provides mechanical straining of particulate waste. It prevents particulate waste from prematurely clogging other filter media in the module stack. Although the primary purpose of Fluval Aquarium Filter Foam Block is mechanical filtration, biological activity will eventually occur within its pore structure. The Fluval Aquarium Filter Foam Block can be used for fresh or marine water aquariums.