Side length: Approximately 51, 57, 56, 51, 54 cm Thickness: Approximately 6cm to 8cm They were the same size initially. The size varies depending on the frequency of use. Basically, the side length was about 50cm, but as they wear out, they become larger while the height decreases. Also, it's difficult to see, but there are some areas that are slightly dirty or faded. Please refrain from purchasing if you are concerned about minor imperfections, as these items have been stored at home for a long time.