DIY Cube Small Aquarium Sponge Filter (Sponge Only) 3.5 x 3.5 x 5 40 Pore Per Inch Reticulated Foam Pre-drilled 1/2" Hole for Pipe Just the Sponge - Use your own lift pipe (PVC, Rigid) Can use with powerheads for better filtration! Highly Efficient Foam won't Break Down