Our aeration system allows the intensity of gases emitted from flower or herbal contents to be released from the canister to preserve freshness and potency. As the air pressure rises within the canister, our one-way valve opens to allow this aeration process to take place. After the gases are released the valve closes, keeping the canister airtight. HerbSafe is totally opaque thereby keeping light, heat, and moisture from affecting its contents. The valve works on its own. You do not need to do anything to it. What is an HerbSafe?