Rare item, Revere ware for the microwave oven or reg. Oven up to 420 (like Littonware or Tupperware ultra 21 or anchor Hocking microwave) this is hard melmac. It measures 9 inches around and says divided casserole/cover. It holds 1 quart. It has the Paul revere head symbol too, see pictures. They enlarge too. It is cream colored. Can be used by itself or as part of a set.