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 Z Large - 64 oz Charbon/Zeo 1840G - GM. High quality blend of Pro-Carb and Pro-Z Activated Carbon and Ammonia-Removing Zeolite Crystals Higher absorptive capacity than other premium brands. Category: Aquarium Supplies/Maintenance. Sub Category: Filter Cartridges. Cubes: 0.0044. Weight: 4.7500.