LTWHOME 8 Inch / 20cm Coarse Pond Filter Foam Cube Block Pump Pre Sponge (Pack of 1)

has an off centre hole cut out (3.5" Diameter x 5.5" deep) - Coarse grade foam,Cuts Easy To Any Required Shape Package Include:1PCS 6" Inch Coarse Pond Filter Foam Good for freshwater & marine environments Traps Particles & Debris Enhances biological filtration