PLEASE NOTE: I myself do not have post-it sticky notes. The dimensions should be correct and should fit most Sticky Notes, especially with the Post-It sticky notes in mind. But, I myself have not tested it since I can't, but please let me know if it fits.

In this improved version I have made it slightly larger to accommodate larger Sticky Notes, after it has been brought to my attention that Post-It sticky notes wouldn't fit in the old version.

This is a GridFinity 2x2 sticky notes holder, it was designed for sticky notes that are roughly 76x76mm, but slightly larger should be okay, as long as you do not exceed 79x79mm, that will definitely not fit. It is stackable so u could put other gridfinity containers on top. Let me know if you have any questions!