These boxes come sized at approximately 2-1/2" x 2-1/2" x 2" and is compatible with both the 8x12 and 12x12 mats.  The file comes with the box base, coordinating mats, and paper elements shown.  The boxes can be made smaller or larger to fit your needs.  See more here: https://jamielanedesigns.blogspot.com/2017/11/holiday-favor-boxes.html