Herbsafe (mini) HerbSafe stainless steel containers use a patent-pending silicon valve. The one-way pressure release valve keeps air and moisture out, while allowing CO2 to escape. Clip down the lid, and the silicon seal activates to keep out any gases, and eliminates a drying effect. Our patent-pending pressure release valve never needs to be replaced and is dishwasher safe. You do not need to do anything to it. Comes in Mini and Large size stainless steel canisters, with a BPA-free polypropylene lid including our patent-pending one-way silicon valve