Air takes out the freshness, EVAK takes out the air! The longer your food 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 food. Evacuate the air and keep your food fresher and longer with EVAK glass storage containers by Prepara. Scientifically tested. Our Evak container was tested against the leading brand of storage container and there was no comparison. The Evak locked in flavors for longer and kept contents fresher. Still not convinced?...try one- we have a 5 year guarantee for satisfaction and quality. We are sure you'll love it. It's so simple- just push down, then pull up; no buttons or levers.