These window top round tin containers are seamlessly formed of 100% steel (.24 mm metal) and come with a beveled bottom which makes them stackable. The slip on cover has a clear window insert that allows for easy visibility. All lids and bottom edges are rounded for safety. The product includes the cover and bottom and is shipped assembled. Dimensions are of outside measurements. Our tin cans are made of 100% steel and do not have an internal plastic lining, therefore caustic substances may cause the steel to rust. For rust-resistant tins look here.