I cannot tell you how much I love this product! I purchased the square covers, because most of my containers are square, however I use the covers for square and round containers. They stretch easily, so they fit many different sizes and the fit is secure. I've had them for about a month and they haven't lost any elasticity. I was hesitant to use in the microwave, but now that I do, there is no hesitation at all. I wash by hand, only because I use them so often. They are easy to clean and v...