Container & Cargo Dry With Hanging Hook by Dry-Packs - 4.5LBS & 2KG - Product comes ready to use! Just open outer package and install (use). - Quantity needed to cover 20' container is 10 bags. For 40' container use 20 bags. Total can vary depending on length of storage, product type, etc. - Large 4.5LB Bag with sturdy hanging hook. Ready to absorb moisture and protect your items! - Protect from "Container Rain" in cargo containers. Can also use in garages, boats, closets, basements, crawlspaces, etc. - Protect your valuables from moisture problems including Mildew, Mold, and Corrosion.