Penn Plax is a name that stands for Quality Innovation and Integrity In the Pet Industry for over 50 years Experience a great line of Pet Products in all categories! Penn-Plax is committed to creating and manufacturing innovative pet products for first-time pet owners and serious hobbyists alike. Pro-Carb - Medium 28 oz. Charbon 815G - MM. For Crystal-Clear Water Long-Lasting Fast-Acting Removes harmful chemicals toxins odors discolorations and other contaminants. Category: Aquarium Supplies/Maintenance. Sub Category: Filter Cartridges. Cubes: 0.0025. Weight: 2.2600.