This Sticky Note Holder has three slots to hold three 3" x 3" Sticky Note Pads .  The holder is approximately 4-1/2" x 4-1/4" x 2-1/2" when assembles.  The slots are approximately 3".  The file is compatible with both the 8x12 and 12x12 mats and comes with the wrap, the box base, an inside slot insert (for stability) and the main slot insert.  

https://jamielanedesigns.blogspot.com/2018/12/sticky-note-holder.html