This is a jello mold or punch ice ring mold. This can not be used for baking. It can be used for anything cold but can not handle heat and could make you sick if baked in. I use them all the time and they are great for making ice rings for parties. Just add sliced oranges, strawberries, grapes or any fruit and fill with water and freeze.
I wasn't sure what to call this but it is metal and I assumed it was for a cake that you put pudding or fruit in the middle. I don't know much about it though because it was left by a roommate...