This Heart Box box opens from the top and can be sized to fit your needs. The top has a tuck-in flap for easy access! As it comes, the box is approximately 6-1/4" x 7" x 1-3/4" and is compatible with both 8x12 and 12x12 mats. You can see more on my blog here: https://jamielanedesigns.blogspot.com/2018/12/heart-boxes.html