Tightvacs are vacuum-sealed, airtight, and smell-proof containers. A 2-way valve system allows gasses to escape without allowing air to enter, this helps preserve the contents for longer but can potentially let odors escape too. To prevent the release of unwanted odors, we recommend putting any especially fragrant herbs or spices into a sealed plastic bag first. This will also help keep your Tightvac clean from residue that could reduce the effectiveness of the seal, and potentially damage the plastic. To open your Tightvac simply press the front button while gently pulling the cap up, when you want to close the container make sure you also hold the front button as this is what allows the air to escape and create a vacuum.