maintaining 7am to 13 pm in warmth despite the boiling water into the outer container and the transition to strong micro wave. Hermetic for compact products. The untested liquid. After 3 uses, washes, and left in the open air, the cups always have an unpleasant odor that spreads a little food. To see in time. I think it is necessary to heat his food and then put in the cups and not do so directly with micro wave warming cups.