This heart box is approximately 4" x 2" x 1-3/4" in size and is compatible with both the 8x12 and 12x12 mats. The file comes with the one piece box base and the coordinating mats with hearts. The box is top opening making it easy to fill and easy to open/close! This is a great box for making in bulk! See a full tutorial and more images on my blog! https://jamielanedesigns.blogspot.com/2019/01/valentine-gift-boxes.html