It fits a decent (i.e. filling but not fattening) portion of food, vents for the microwave, AND is freezer-, fridge-, microwave-, and oven-safe. We’ve been bringing pasta with cheese on top for lunch and we can get it hot enough to completely melt the cheese while still being able to pick up the mug to eat. Should also be great for stews in the wintertime and even cold foods. I call that a win.
$10 at Amazon, but we found them for $9 at Wegman’s.