100 microm fiter sock bags provide excellent mechanical filtration, which helps reduce the amount of ammonia-producing organic matter in your aquarium by trapping debris which also helps prevent large and small object like sand and coral from damaging aquarium equipment. Solid construction and heavy duty stitching make these socks strong and durable so they can be CLEANED and REUSED NUMEROUS TIMES Aquarium filter bag can effectively improve the quality of aquarium tank water, can perfect trap uneaten food, waste excreted by livestock, decaying plants, detritus, dust, and other floating particulates. Help fish or shrimp have a healthy and clean living environment Suitable for aquarium, fish tank, beverages, chemical industry, etc. Each pack comes with 5pcs bags.