Should have read the reviews on this square more closely. I can't find anywhere on the list that it's plastic. Plastic has some advantages, but I was expecting metal. Since using it for a few days, I've found that I like its light weight, high visibility, and sturdiness to last as long as aluminum, and this one doesn't rust or corrode. After using it for a few days, it still remains boxy with my square steel frame. If I ever need to replace it I will buy another one of these.