Super activated carbon for freshwater and marine systems. Three 4 ounce bags. Use in aquarium filters, terrarium filters, & hydroponic systems. Super-Activated carbon granules absorb many disolved containinants, odor, toxins, and discoloration. Use with Aquarium Masters Bio Rings media to promote colonization of beneficial bacteria essential to a healthy aquatic environment. Convenient 12 ounce size package, contain three 4 ounce bags. Designed to more effective in removing harmful chemicals, increasing the health of your fish or reptiles. We are committed to bringing consumers and service technicians the highest quality products for the most competitive prices. We value your support and want to provide 100% satisfaction, so please feel free to contact us if you're not 100% satisfied.