Marina Foam keeps aquarium water clean and healthy by removing particles and debris. Suitable for use in Fluval EVO 13.5 Gallon Aquarium and Fluval SPEC 16 Gallon Aqauarium Replacement Foam Filter Block Traps Large Particles and Debris Helps Keep Your Aquarium Crystal Clear For Fluval EVO 13.5 and SPEC 16 Gallon Aquariums