I CANNOT tell you how disappointed and frightened we were when the smallest pot cover exploded without any reason at the first night we received the package!!!! We DID NOT do anything but put it on the stove, and that time we thought that was something wrong with the delivery(after 4 hours we opened the package?!), but about four days ago the biggest one exploded too just like the smallest one when we put it on the plate holder to dry it in the air.......anyway, thankfully no one got hurt!!!!!SO DISAPPOINTED!!!