Simplest stackable shelf

Hello friends,I know there are a lot of such shelves here on MW, but I like to build things my own way :-) I wanted to create the simplest shelf that can be placed on a horizontal surface and is stackable at the same time :-) Maybe you will find it useful ;-) I am adding 2 printing profiles, for PLA and PETG, however, for strength, I recommend printing from PETG, at the same time, you can choose between a full or lightweight version, which will save filament at the expense of lower load capacity ;-)