Fluval C2 Foam Pad (3-Pack) – Three replacement foam pads for the Fluval C2 Power Filter’s first-stage filtration. These pads are custom-cut to slide into the C2 filter and are made of coarse, porous foam that efficiently traps large debris and waste particles. Routine replacement of C2 foam pads ensures optimal mechanical filtration, preventing clogging and helping extend the life of subsequent media (chemical and biological) in the filter system.