The double layer lid prevents stag from breaking through fine filters. Conventional sandwich sheets allow flies to be removed if they are rough, and the fineness will lead to accident such as acid deficiency. Traditional sandwich sheets are lifted from the bottom to create a gap in the top to prevent the filter from falling off. The same size as traditional mini placket, making it convenient for shelves, layout, and stacking. Just replace the lid of the product. Fully compatible and can be used as is as is. There are cases where the conventional top slits are used to prevent accidents such as chin breakage due to the circumstance of the shipping company. Regarding breakage, we will send the replacement product the same day you contact us, so we apologize for inconvenience and inconvenience but we appreciate your reference. We will refuse any transactions in the future and will take legal action in case of malicious quality.