Harvest Keeper? HumiGuard Clamp Sealing Stainless Steel Containers are a great storage solution for herbs, dried produce, spices, seeds and dozens of other items! These food grade Stainless Steel HumiGuard Clamp Containers deliver freshness with an air-tight seal. The metal clamp locking closure insures the 1/4 inch wide silicone gasket provides a strong, secure seal to ensure air-tightness. The underside of the lid features a built in pack holder which is specially designed to hold a 4 gm, 8 gm or 67 gm Integra Boost? humidity pack (sold separately).