Which Solar Cooker is the best?

I think that the best solar cooker is this one that is shaped like a funnel. I found a solar cooker that was in the shape of a funnel. It had 3 metal sides and it has a round middle so you can put a pan in it. The materials need are, cardboard boxes, aluminum foil,glue, and scissors/knives. The light reflects off of each of the 3 sides with one opening. There is a metal disk at the botom and it gets really hot and you put the food on there. The durability is good on this. It cooks fast and you can cook all different types of things. It can also be used as a refrigerator.