Professional cookware used for low temperature, vacuum-seal, even-heat-distribution, no or low-oil, no-water cooking resulting in the highest nutrient and flavor retention.  The lid has a visual indicator so you can monitor the ideal temperature inside the unit. No more pot watching or lid lifting! Minimum Moisture and Waterless Cookware --- Multi-layers of heat conducting metals spread heat quickly and evenly eliminating the need for oil. A vapor seal creates a vacuum in each pan and eliminates the need for excess water as well. Foods prepared the waterless, low-temperature way retain more vitamins and minerals.