This file is approximately 1" x 8-3/4" x 2-1/2" and it contains nine slots that will hold small ribbon spools and washi tapes. The file comes with the box base, the slotted box top insert, as well as three different side panels that you can use if you are putting together multiples. There is a side panel for 2, 3, and 4 trays. The image shown with three trays is using the three side panel (the single tray does not require a side panel). This file is compatible with both the 8x12 and 12x12 mats. When four trays are used, you can store 36 rolls! You can find additional images on my blog:  http://jamielanedesigns.blogspot.com/2014/02/expandable-washi-tape-and-ribbon-tray.html