These silica gel packets are ideal for humidity control in enclosed environments. Helps to prevent rust, mold and mildew due to condensation. Use them in ammo cans, gun cases, knife cases, small safes, tool boxes, etc. On average 45 grams of desiccant protects about three cubic feet of a sealed area. Each packet contains 15 grams of silica gel. Each bag holds 15 packets for a total of 150 grams of silica gel desiccant. Replace packets regularly.