Air takes out the freshness…so EVAK takes out the air. The longer your herb is exposed to air, the faster it loses flavor. Glass containers with air-tight lids are readily available, but they trap stale air in with your precious herb. Evacuate the air and keep your herb fresher, longer. Our twin valve system automatically forces the air out as you push down the lid, and lets you easily pull up and remove the lid. It’s so simple-just push down, then pull up; no buttons or levers.