Keep your Marineland Penguin Pro filter running smoothly with these Rite-Size
B 6 Count Cartridges. Designed for all water types, these cartridges are
perfect for the Penguin Pro 100, 125, and 175 models. Made in the United
States, these cartridges are a reliable choice for your filtration needs. With
a unit quantity of 1, it's easy to stock up on these filters for your aquarium.